rtc: da9063: convert header to SPDX

Covnert the header of the source file to SPDX.
Signed-off-by: NWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-da9063.c

-/* rtc-da9063.c - Real time clock device driver for DA9063
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Real time clock device driver for DA9063
  * Copyright (C) 2013-2015  Dialog Semiconductor Ltd.
- *
- * 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.
- *
- * 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.
  */
 
 #include <linux/delay.h>