Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/sh/include/asm/fb.h b/arch/sh/include/asm/fb.h
index d92e99c..9a0bca2 100644
--- a/arch/sh/include/asm/fb.h
+++ b/arch/sh/include/asm/fb.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _ASM_FB_H_
 #define _ASM_FB_H_