gpio: tps68470: Update to SPDX license identifier

Remove the GPL v2 license boilerplate and update with
the SPDX license identifier.
Signed-off-by: Rajmohan Mani <rajmohan.mani@intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-tps68470.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * GPIO driver for TPS68470 PMIC
  *
@@ -8,15 +9,6 @@
  *	Tianshu Qiu <tian.shu.qiu@intel.com>
  *	Jian Xu Zheng <jian.xu.zheng@intel.com>
  *	Yuning Pu <yuning.pu@intel.com>
- *
- * 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 version 2.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
  */
 
 #include <linux/gpio/driver.h>