Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/uapi/linux/pg.h b/include/uapi/linux/pg.h
index 364c350..62b6f69 100644
--- a/include/uapi/linux/pg.h
+++ b/include/uapi/linux/pg.h
@@ -35,6 +35,9 @@
 
 */
 
+#ifndef _UAPI_LINUX_PG_H
+#define _UAPI_LINUX_PG_H
+
 #define PG_MAGIC	'P'
 #define PG_RESET	'Z'
 #define PG_COMMAND	'C'
@@ -61,4 +64,4 @@
 
 };
 
-/* end of pg.h */
+#endif /* _UAPI_LINUX_PG_H */