Update to v6.12 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-6.12

Comment out the TAG usage of the __struct_group macro in linux/pkt_cls.h.
The kernel upstream is either going to revert this usage of __struct_group
or fix this in another way. When set, it creates a named struct in an
anonyous union, which is not allowed in C++.

Test: Builds and bionic unit tests pass on raven.
Change-Id: Ibb49550dfdc86fa0fc888b51d893959b6d433c59
diff --git a/libc/kernel/uapi/linux/ioam6_iptunnel.h b/libc/kernel/uapi/linux/ioam6_iptunnel.h
index 34317fc..e1a0223 100644
--- a/libc/kernel/uapi/linux/ioam6_iptunnel.h
+++ b/libc/kernel/uapi/linux/ioam6_iptunnel.h
@@ -24,6 +24,7 @@
 #define IOAM6_IPTUNNEL_FREQ_MAX 1000000
   IOAM6_IPTUNNEL_FREQ_K,
   IOAM6_IPTUNNEL_FREQ_N,
+  IOAM6_IPTUNNEL_SRC,
   __IOAM6_IPTUNNEL_MAX,
 };
 #define IOAM6_IPTUNNEL_MAX (__IOAM6_IPTUNNEL_MAX - 1)