soc: samsung: Add SPDX license identifiers

Replace GPL license statements with SPDX GPL-2.0 license identifiers.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
diff --git a/drivers/soc/samsung/exynos5420-pmu.c b/drivers/soc/samsung/exynos5420-pmu.c
index 0a89fa7..b236d3b 100644
--- a/drivers/soc/samsung/exynos5420-pmu.c
+++ b/drivers/soc/samsung/exynos5420-pmu.c
@@ -1,13 +1,9 @@
-/*
- * Copyright (c) 2011-2015 Samsung Electronics Co., Ltd.
- *		http://www.samsung.com/
- *
- * EXYNOS5420 - CPU PMU (Power Management Unit) support
- *
- * 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.
- */
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2011-2015 Samsung Electronics Co., Ltd.
+//		http://www.samsung.com/
+//
+// EXYNOS5420 - CPU PMU (Power Management Unit) support
 
 #include <linux/pm.h>
 #include <linux/soc/samsung/exynos-regs-pmu.h>