mfd: 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: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/tps68470.c b/drivers/mfd/tps68470.c
index 189efae..a5981a7 100644
--- a/drivers/mfd/tps68470.c
+++ b/drivers/mfd/tps68470.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * TPS68470 chip Parent driver
  *
@@ -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/acpi.h>