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/if_arp.h b/libc/kernel/uapi/linux/if_arp.h
index eda888f..1cd23ef 100644
--- a/libc/kernel/uapi/linux/if_arp.h
+++ b/libc/kernel/uapi/linux/if_arp.h
@@ -44,6 +44,7 @@
 #define ARPHRD_X25 271
 #define ARPHRD_HWX25 272
 #define ARPHRD_CAN 280
+#define ARPHRD_MCTP 290
 #define ARPHRD_PPP 512
 #define ARPHRD_CISCO 513
 #define ARPHRD_HDLC ARPHRD_CISCO