Update to v5.15 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-5.15

Test: Builds, and ran bionic unit tests on flame.
Change-Id: I86901ea6d89fb0f7384b90a47bef35d194083c24
diff --git a/libc/kernel/uapi/linux/ipv6.h b/libc/kernel/uapi/linux/ipv6.h
index 438cacc..14c818c 100644
--- a/libc/kernel/uapi/linux/ipv6.h
+++ b/libc/kernel/uapi/linux/ipv6.h
@@ -144,6 +144,9 @@
   DEVCONF_NDISC_TCLASS,
   DEVCONF_RPL_SEG_ENABLED,
   DEVCONF_RA_DEFRTR_METRIC,
+  DEVCONF_IOAM6_ENABLED,
+  DEVCONF_IOAM6_ID,
+  DEVCONF_IOAM6_ID_WIDE,
   DEVCONF_MAX
 };
 #endif