Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/mach-ixp4xx/nslu2-pci.c b/arch/arm/mach-ixp4xx/nslu2-pci.c
index 032defe..c07936a 100644
--- a/arch/arm/mach-ixp4xx/nslu2-pci.c
+++ b/arch/arm/mach-ixp4xx/nslu2-pci.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * arch/arm/mach-ixp4xx/nslu2-pci.c
  *
@@ -8,11 +9,6 @@
  *	Copyright (C) 2003-2004 MontaVista Software, Inc.
  *
  * Maintainer: http://www.nslu2-linux.org/
- *
- * 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.
- *
  */
 
 #include <linux/pci.h>
@@ -21,6 +17,8 @@
 #include <asm/mach/pci.h>
 #include <asm/mach-types.h>
 
+#include "irqs.h"
+
 #define MAX_DEV		3
 #define IRQ_LINES	3