memory: emif-asm-offsets: Add GPLv2 SPDX license header

Add GPLv2 license header and remove GPL boiler plate text.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

drivers/memory/emif-asm-offsets.c

+// SPDX-License-Identifier: GPL-2.0
 /*
  * TI AM33XX EMIF PM Assembly Offsets
  *
  * Copyright (C) 2016-2017 Texas Instruments Inc.
- *
- * 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/ti-emif-sram.h>