Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/iio/adc/viperboard_adc.c b/drivers/iio/adc/viperboard_adc.c
index 53eb5a4..1d2aeb0 100644
--- a/drivers/iio/adc/viperboard_adc.c
+++ b/drivers/iio/adc/viperboard_adc.c
@@ -1,15 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  Nano River Technologies viperboard IIO ADC driver
  *
  *  (C) 2012 by Lemonage GmbH
  *  Author: Lars Poeschel <poeschel@lemonage.de>
  *  All rights reserved.
- *
- *  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/kernel.h>