Update to v5.6 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-5.6

Add a new method for removing structures. This is to deal with the kernel
headers changing some definitions of timeval to __kernel_old_timeval
and itimerval to __kernel_old_itimerval. Remove the __kernel_old_XX
strutures and change the other structures to the previous definitions.

This only works so long as these structures stay the same, if they
diverge, then a different strategy will need to be implemented.

Test: Booted cuttlefish/walleye.
Test: Ran bionic-unit-tests on cuttlefish/walleye.
Change-Id: I0a61f4fa6e4155c602e0414d9b38c2e1637829af
diff --git a/libc/kernel/uapi/linux/openvswitch.h b/libc/kernel/uapi/linux/openvswitch.h
index 99a987d..05d750a 100644
--- a/libc/kernel/uapi/linux/openvswitch.h
+++ b/libc/kernel/uapi/linux/openvswitch.h
@@ -366,6 +366,12 @@
   __be32 mpls_lse;
   __be16 mpls_ethertype;
 };
+struct ovs_action_add_mpls {
+  __be32 mpls_lse;
+  __be16 mpls_ethertype;
+  __u16 tun_flags;
+};
+#define OVS_MPLS_L3_TUNNEL_FLAG_MASK (1 << 0)
 struct ovs_action_push_vlan {
   __be16 vlan_tpid;
   __be16 vlan_tci;
@@ -439,6 +445,7 @@
   OVS_ACTION_ATTR_METER,
   OVS_ACTION_ATTR_CLONE,
   OVS_ACTION_ATTR_CHECK_PKT_LEN,
+  OVS_ACTION_ATTR_ADD_MPLS,
   __OVS_ACTION_ATTR_MAX,
 };
 #define OVS_ACTION_ATTR_MAX (__OVS_ACTION_ATTR_MAX - 1)