Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/dma/hsu/hsu.h b/drivers/dma/hsu/hsu.h
index 486b023..9e59563 100644
--- a/drivers/dma/hsu/hsu.h
+++ b/drivers/dma/hsu/hsu.h
@@ -1,13 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Driver for the High Speed UART DMA
  *
  * Copyright (C) 2015 Intel Corporation
  *
  * Partially based on the bits found in drivers/tty/serial/mfd.c.
- *
- * 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.
  */
 
 #ifndef __DMA_HSU_H__