Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/sound/ac97_bus.c b/sound/ac97_bus.c
index 52e4bc5..3732a63 100644
--- a/sound/ac97_bus.c
+++ b/sound/ac97_bus.c
@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Linux driver model AC97 bus interface
  *
  * Author:	Nicolas Pitre
  * Created:	Jan 14, 2005
  * Copyright:	(C) MontaVista Software Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
  */
 
 #include <linux/module.h>