Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/root_dev.h b/include/linux/root_dev.h
index bab671b..4e78651 100644
--- a/include/linux/root_dev.h
+++ b/include/linux/root_dev.h
@@ -8,6 +8,7 @@
 
 enum {
 	Root_NFS = MKDEV(UNNAMED_MAJOR, 255),
+	Root_CIFS = MKDEV(UNNAMED_MAJOR, 254),
 	Root_RAM0 = MKDEV(RAMDISK_MAJOR, 0),
 	Root_RAM1 = MKDEV(RAMDISK_MAJOR, 1),
 	Root_FD0 = MKDEV(FLOPPY_MAJOR, 0),