Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/mach-gemini/Kconfig b/arch/arm/mach-gemini/Kconfig
index 70106b6..969674e 100644
--- a/arch/arm/mach-gemini/Kconfig
+++ b/arch/arm/mach-gemini/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 menuconfig ARCH_GEMINI
 	bool "Cortina Systems Gemini"
 	depends on ARCH_MULTI_V4
diff --git a/arch/arm/mach-gemini/Makefile b/arch/arm/mach-gemini/Makefile
index ca0db54..997a0be 100644
--- a/arch/arm/mach-gemini/Makefile
+++ b/arch/arm/mach-gemini/Makefile
@@ -1,2 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
 # Makefile for Cortina systems Gemini
 obj-y			:= board-dt.o