Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/iio/dac/ad5504.c b/drivers/iio/dac/ad5504.c
index d9037ea..c64e689 100644
--- a/drivers/iio/dac/ad5504.c
+++ b/drivers/iio/dac/ad5504.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * AD5504, AD5501 High Voltage Digital to Analog Converter
  *
  * Copyright 2011 Analog Devices Inc.
- *
- * Licensed under the GPL-2.
  */
 
 #include <linux/interrupt.h>
@@ -369,6 +368,6 @@
 };
 module_spi_driver(ad5504_driver);
 
-MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC");
 MODULE_LICENSE("GPL v2");