ASoC: samsung: smdk_spdif: Convert to SPDX License Identifier

Replace GPL v2.0+ license statements with SPDX license identifier.
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

sound/soc/samsung/smdk_spdif.c

-/*
- * smdk_spdif.c  --  S/PDIF audio for SMDK
- *
- * Copyright 2010 Samsung Electronics Co. Ltd.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- */
+// SPDX-License-Identifier: GPL-2.0+
+//
+// smdk_spdif.c - S/PDIF audio for SMDK
+//
+// Copyright (C) 2010 Samsung Electronics Co., Ltd.
 
 #include <linux/clk.h>
 #include <linux/module.h>