Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/video/backlight/generic_bl.c b/drivers/video/backlight/generic_bl.c
index 4dea91a..8fe63db 100644
--- a/drivers/video/backlight/generic_bl.c
+++ b/drivers/video/backlight/generic_bl.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Generic Backlight Driver
  *
  *  Copyright (c) 2004-2008 Richard Purdie
- *
- *  This program is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License version 2 as
- *  published by the Free Software Foundation.
- *
  */
 
 #include <linux/module.h>