regulator: as3711: 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/as3711-regulator.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * AS3711 PMIC regulator driver, using DCDC Step Down and LDO supplies
  *
  * Copyright (C) 2012 Renesas Electronics Corporation
  * Author: Guennadi Liakhovetski, <g.liakhovetski@gmx.de>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the version 2 of the GNU General Public License as
- * published by the Free Software Foundation
  */
 
 #include <linux/err.h>