Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/iio/adc/xilinx-xadc.h b/drivers/iio/adc/xilinx-xadc.h
index 8c00095..4017f18 100644
--- a/drivers/iio/adc/xilinx-xadc.h
+++ b/drivers/iio/adc/xilinx-xadc.h
@@ -1,10 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Xilinx XADC driver
  *
  * Copyright 2013 Analog Devices Inc.
  *  Author: Lars-Peter Clauen <lars@metafoo.de>
- *
- * Licensed under the GPL-2.
  */
 
 #ifndef __IIO_XILINX_XADC__