ASoC: samsung: snow: Convert to SPDX License Identifier

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

sound/soc/samsung/snow.c

-/*
- * ASoC machine driver for Snow boards
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- */
+// SPDX-License-Identifier: GPL-2.0
+//
+// ASoC machine driver for Snow boards
 
 #include <linux/clk.h>
 #include <linux/module.h>