Updated to v4.4.1 kernel headers.

Small modifications needed to allow compilation with the new headers:

- Manually modify bionic/libc/kernel/uapi/asm-mips/asm/siginfo.h to
  remove the uapi from the include.
- PR_XXX defines are now available for mips, so remove the definition
  from linker_mips.cpp.

Bug: 23789423
Change-Id: I6dc8a03b012426d3a937db15cb24d3a50fab5a8c
diff --git a/libc/kernel/uapi/linux/l2tp.h b/libc/kernel/uapi/linux/l2tp.h
index 4eaf7ad..cb1504b 100644
--- a/libc/kernel/uapi/linux/l2tp.h
+++ b/libc/kernel/uapi/linux/l2tp.h
@@ -154,5 +154,6 @@
 };
 #define L2TP_GENL_NAME "l2tp"
 #define L2TP_GENL_VERSION 0x1
-#endif
+#define L2TP_GENL_MCGROUP "l2tp"
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#endif