dmaengine: jz4780: Use SPDX license notifier

Use SPDX license notifier instead of plain text in the header.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/dma-jz4780.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Ingenic JZ4780 DMA controller
  *
  * Copyright (c) 2015 Imagination Technologies
  * Author: Alex Smith <alex@alex-smith.me.uk>
- *
- * 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/clk.h>