Update to v5.12 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-5.12

Test: Boots flame device and runs bionic unit tests.
Test: Boots acloud device and runs bionic unit tests.

Change-Id: I8ac107ce9d4978be3ef9517b90ad6ecafd06785a
diff --git a/libc/kernel/uapi/linux/l2tp.h b/libc/kernel/uapi/linux/l2tp.h
index c65f7a9..a054819 100644
--- a/libc/kernel/uapi/linux/l2tp.h
+++ b/libc/kernel/uapi/linux/l2tp.h
@@ -104,6 +104,7 @@
   L2TP_ATTR_RX_ERRORS,
   L2TP_ATTR_STATS_PAD,
   L2TP_ATTR_RX_COOKIE_DISCARDS,
+  L2TP_ATTR_RX_INVALID,
   __L2TP_ATTR_STATS_MAX,
 };
 #define L2TP_ATTR_STATS_MAX (__L2TP_ATTR_STATS_MAX - 1)