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/if_macsec.h b/libc/kernel/uapi/linux/if_macsec.h
index a58f531..d77bf21 100644
--- a/libc/kernel/uapi/linux/if_macsec.h
+++ b/libc/kernel/uapi/linux/if_macsec.h
@@ -40,6 +40,7 @@
   MACSEC_ATTR_RXSC_LIST,
   MACSEC_ATTR_TXSC_STATS,
   MACSEC_ATTR_SECY_STATS,
+  MACSEC_ATTR_OFFLOAD,
   __MACSEC_ATTR_END,
   NUM_MACSEC_ATTR = __MACSEC_ATTR_END,
   MACSEC_ATTR_MAX = __MACSEC_ATTR_END - 1,
@@ -88,6 +89,14 @@
   NUM_MACSEC_SA_ATTR = __MACSEC_SA_ATTR_END,
   MACSEC_SA_ATTR_MAX = __MACSEC_SA_ATTR_END - 1,
 };
+enum macsec_offload_attrs {
+  MACSEC_OFFLOAD_ATTR_UNSPEC,
+  MACSEC_OFFLOAD_ATTR_TYPE,
+  MACSEC_OFFLOAD_ATTR_PAD,
+  __MACSEC_OFFLOAD_ATTR_END,
+  NUM_MACSEC_OFFLOAD_ATTR = __MACSEC_OFFLOAD_ATTR_END,
+  MACSEC_OFFLOAD_ATTR_MAX = __MACSEC_OFFLOAD_ATTR_END - 1,
+};
 enum macsec_nl_commands {
   MACSEC_CMD_GET_TXSC,
   MACSEC_CMD_ADD_RXSC,
@@ -99,6 +108,7 @@
   MACSEC_CMD_ADD_RXSA,
   MACSEC_CMD_DEL_RXSA,
   MACSEC_CMD_UPD_RXSA,
+  MACSEC_CMD_UPD_OFFLOAD,
 };
 enum macsec_rxsc_stats_attr {
   MACSEC_RXSC_STATS_ATTR_UNSPEC,