Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/kernel/dma.c b/arch/arm/kernel/dma.c
index 6739d37..ba15b86 100644
--- a/arch/arm/kernel/dma.c
+++ b/arch/arm/kernel/dma.c
@@ -1,12 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/arch/arm/kernel/dma.c
  *
  *  Copyright (C) 1995-2000 Russell King
  *
- * 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.
- *
  *  Front-end to the DMA handling.  This handles the allocation/freeing
  *  of DMA channels, and provides a unified interface to the machines
  *  DMA facilities.