regulator: bd9571mwv: convert to SPDX identifiers

This patch updates license to use SPDX-License-Identifier
instead of verbose license text.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/bd9571mwv-regulator.c

@@ -1,17 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * ROHM BD9571MWV-M regulator driver
  *
  * Copyright (C) 2017 Marek Vasut <marek.vasut+renesas@gmail.com>
  *
- * 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 "as is" WITHOUT ANY WARRANTY of any
- * kind, whether expressed or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License version 2 for more details.
- *
  * Based on the TPS65086 driver
  *
  * NOTE: VD09 is missing