pinctrl: rza1: 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>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

drivers/pinctrl/pinctrl-rza1.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * Combined GPIO and pin controller support for Renesas RZ/A1 (r7s72100) SoC
  *
  * Copyright (C) 2017 Jacopo Mondi
- *
- * This file is licensed under the terms of the GNU General Public
- * License version 2. This program is licensed "as is" without any
- * warranty of any kind, whether express or implied.
  */
 
 /*