sata_rcar: 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: Jens Axboe <axboe@kernel.dk>

drivers/ata/sata_rcar.c

@@ -1,14 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Renesas R-Car SATA driver
  *
  * Author: Vladimir Barinov <source@cogentembedded.com>
  * Copyright (C) 2013-2015 Cogent Embedded, Inc.
  * Copyright (C) 2013-2015 Renesas Solutions Corp.
- *
- * 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.
  */
 
 #include <linux/kernel.h>