Update to android-mainline kernel headers v5.4.

Update generate_uapi_headers.sh to checkout the android mainline
kernel. Also, add a small modification to look for the kernel directory
in common not linux-stable.

Remove deprecated android headers from android/uapi/linux. Also,
remove f_accessory.h since it's in the android mainline kernel.

Test: Builds and runs on walleye.
Change-Id: Ia371305e19f56e6bcc2db6d5b4d299819f07ffc6
diff --git a/libc/kernel/uapi/linux/bpf.h b/libc/kernel/uapi/linux/bpf.h
index 7e78758..39a9ea6 100644
--- a/libc/kernel/uapi/linux/bpf.h
+++ b/libc/kernel/uapi/linux/bpf.h
@@ -94,6 +94,7 @@
   BPF_TASK_FD_QUERY,
   BPF_MAP_LOOKUP_AND_DELETE_ELEM,
   BPF_MAP_FREEZE,
+  BPF_BTF_GET_NEXT_ID,
 };
 enum bpf_map_type {
   BPF_MAP_TYPE_UNSPEC,
@@ -121,6 +122,7 @@
   BPF_MAP_TYPE_QUEUE,
   BPF_MAP_TYPE_STACK,
   BPF_MAP_TYPE_SK_STORAGE,
+  BPF_MAP_TYPE_DEVMAP_HASH,
 };
 enum bpf_prog_type {
   BPF_PROG_TYPE_UNSPEC,
@@ -182,6 +184,7 @@
 #define BPF_F_STRICT_ALIGNMENT (1U << 0)
 #define BPF_F_ANY_ALIGNMENT (1U << 1)
 #define BPF_F_TEST_RND_HI32 (1U << 2)
+#define BPF_F_TEST_STATE_FREQ (1U << 3)
 #define BPF_PSEUDO_MAP_FD 1
 #define BPF_PSEUDO_MAP_VALUE 2
 #define BPF_PSEUDO_CALL 1
@@ -199,6 +202,7 @@
 #define BPF_F_ZERO_SEED (1U << 6)
 #define BPF_F_RDONLY_PROG (1U << 7)
 #define BPF_F_WRONLY_PROG (1U << 8)
+#define BPF_F_CLONE (1U << 9)
 #define BPF_F_QUERY_EFFECTIVE (1U << 0)
 enum bpf_stack_build_id_status {
   BPF_STACK_BUILD_ID_EMPTY = 0,
@@ -330,7 +334,7 @@
     __u64 probe_addr;
   } task_fd_query;
 } __attribute__((aligned(8)));
-#define __BPF_FUNC_MAPPER(FN) FN(unspec), FN(map_lookup_elem), FN(map_update_elem), FN(map_delete_elem), FN(probe_read), FN(ktime_get_ns), FN(trace_printk), FN(get_prandom_u32), FN(get_smp_processor_id), FN(skb_store_bytes), FN(l3_csum_replace), FN(l4_csum_replace), FN(tail_call), FN(clone_redirect), FN(get_current_pid_tgid), FN(get_current_uid_gid), FN(get_current_comm), FN(get_cgroup_classid), FN(skb_vlan_push), FN(skb_vlan_pop), FN(skb_get_tunnel_key), FN(skb_set_tunnel_key), FN(perf_event_read), FN(redirect), FN(get_route_realm), FN(perf_event_output), FN(skb_load_bytes), FN(get_stackid), FN(csum_diff), FN(skb_get_tunnel_opt), FN(skb_set_tunnel_opt), FN(skb_change_proto), FN(skb_change_type), FN(skb_under_cgroup), FN(get_hash_recalc), FN(get_current_task), FN(probe_write_user), FN(current_task_under_cgroup), FN(skb_change_tail), FN(skb_pull_data), FN(csum_update), FN(set_hash_invalid), FN(get_numa_node_id), FN(skb_change_head), FN(xdp_adjust_head), FN(probe_read_str), FN(get_socket_cookie), FN(get_socket_uid), FN(set_hash), FN(setsockopt), FN(skb_adjust_room), FN(redirect_map), FN(sk_redirect_map), FN(sock_map_update), FN(xdp_adjust_meta), FN(perf_event_read_value), FN(perf_prog_read_value), FN(getsockopt), FN(override_return), FN(sock_ops_cb_flags_set), FN(msg_redirect_map), FN(msg_apply_bytes), FN(msg_cork_bytes), FN(msg_pull_data), FN(bind), FN(xdp_adjust_tail), FN(skb_get_xfrm_state), FN(get_stack), FN(skb_load_bytes_relative), FN(fib_lookup), FN(sock_hash_update), FN(msg_redirect_hash), FN(sk_redirect_hash), FN(lwt_push_encap), FN(lwt_seg6_store_bytes), FN(lwt_seg6_adjust_srh), FN(lwt_seg6_action), FN(rc_repeat), FN(rc_keydown), FN(skb_cgroup_id), FN(get_current_cgroup_id), FN(get_local_storage), FN(sk_select_reuseport), FN(skb_ancestor_cgroup_id), FN(sk_lookup_tcp), FN(sk_lookup_udp), FN(sk_release), FN(map_push_elem), FN(map_pop_elem), FN(map_peek_elem), FN(msg_push_data), FN(msg_pop_data), FN(rc_pointer_rel), FN(spin_lock), FN(spin_unlock), FN(sk_fullsock), FN(tcp_sock), FN(skb_ecn_set_ce), FN(get_listener_sock), FN(skc_lookup_tcp), FN(tcp_check_syncookie), FN(sysctl_get_name), FN(sysctl_get_current_value), FN(sysctl_get_new_value), FN(sysctl_set_new_value), FN(strtol), FN(strtoul), FN(sk_storage_get), FN(sk_storage_delete), FN(send_signal),
+#define __BPF_FUNC_MAPPER(FN) FN(unspec), FN(map_lookup_elem), FN(map_update_elem), FN(map_delete_elem), FN(probe_read), FN(ktime_get_ns), FN(trace_printk), FN(get_prandom_u32), FN(get_smp_processor_id), FN(skb_store_bytes), FN(l3_csum_replace), FN(l4_csum_replace), FN(tail_call), FN(clone_redirect), FN(get_current_pid_tgid), FN(get_current_uid_gid), FN(get_current_comm), FN(get_cgroup_classid), FN(skb_vlan_push), FN(skb_vlan_pop), FN(skb_get_tunnel_key), FN(skb_set_tunnel_key), FN(perf_event_read), FN(redirect), FN(get_route_realm), FN(perf_event_output), FN(skb_load_bytes), FN(get_stackid), FN(csum_diff), FN(skb_get_tunnel_opt), FN(skb_set_tunnel_opt), FN(skb_change_proto), FN(skb_change_type), FN(skb_under_cgroup), FN(get_hash_recalc), FN(get_current_task), FN(probe_write_user), FN(current_task_under_cgroup), FN(skb_change_tail), FN(skb_pull_data), FN(csum_update), FN(set_hash_invalid), FN(get_numa_node_id), FN(skb_change_head), FN(xdp_adjust_head), FN(probe_read_str), FN(get_socket_cookie), FN(get_socket_uid), FN(set_hash), FN(setsockopt), FN(skb_adjust_room), FN(redirect_map), FN(sk_redirect_map), FN(sock_map_update), FN(xdp_adjust_meta), FN(perf_event_read_value), FN(perf_prog_read_value), FN(getsockopt), FN(override_return), FN(sock_ops_cb_flags_set), FN(msg_redirect_map), FN(msg_apply_bytes), FN(msg_cork_bytes), FN(msg_pull_data), FN(bind), FN(xdp_adjust_tail), FN(skb_get_xfrm_state), FN(get_stack), FN(skb_load_bytes_relative), FN(fib_lookup), FN(sock_hash_update), FN(msg_redirect_hash), FN(sk_redirect_hash), FN(lwt_push_encap), FN(lwt_seg6_store_bytes), FN(lwt_seg6_adjust_srh), FN(lwt_seg6_action), FN(rc_repeat), FN(rc_keydown), FN(skb_cgroup_id), FN(get_current_cgroup_id), FN(get_local_storage), FN(sk_select_reuseport), FN(skb_ancestor_cgroup_id), FN(sk_lookup_tcp), FN(sk_lookup_udp), FN(sk_release), FN(map_push_elem), FN(map_pop_elem), FN(map_peek_elem), FN(msg_push_data), FN(msg_pop_data), FN(rc_pointer_rel), FN(spin_lock), FN(spin_unlock), FN(sk_fullsock), FN(tcp_sock), FN(skb_ecn_set_ce), FN(get_listener_sock), FN(skc_lookup_tcp), FN(tcp_check_syncookie), FN(sysctl_get_name), FN(sysctl_get_current_value), FN(sysctl_get_new_value), FN(sysctl_set_new_value), FN(strtol), FN(strtoul), FN(sk_storage_get), FN(sk_storage_delete), FN(send_signal), FN(tcp_gen_syncookie),
 #define __BPF_ENUM_FN(x) BPF_FUNC_ ##x
 enum bpf_func_id {
   __BPF_FUNC_MAPPER(__BPF_ENUM_FN) __BPF_FUNC_MAX_ID,
@@ -757,6 +761,9 @@
   BPF_FD_TYPE_UPROBE,
   BPF_FD_TYPE_URETPROBE,
 };
+#define BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG (1U << 0)
+#define BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL (1U << 1)
+#define BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP (1U << 2)
 struct bpf_flow_keys {
   __u16 nhoff;
   __u16 thoff;
@@ -778,6 +785,8 @@
       __u32 ipv6_dst[4];
     };
   };
+  __u32 flags;
+  __be32 flow_label;
 };
 struct bpf_func_info {
   __u32 insn_off;