Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
index aebf7dd..5f4fb56 100644
--- a/drivers/iio/light/cm32181.c
+++ b/drivers/iio/light/cm32181.c
@@ -1,10 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2013 Capella Microsystems Inc.
  * Author: Kevin Tsai <ktsai@capellamicro.com>
- *
- * 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/delay.h>