ASoC: imx-ssi: use dma_writecombine consistently

If the channel is allocated as writecombine, then mmaping it should also
use writecombine. Also, add a proper device for the call. Ported from a
similar fix for mach-mxs.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/imx/imx-ssi.c

@@ -357,8 +357,8 @@ int snd_imx_pcm_mmap(struct snd_pcm_substream *substream,
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	int ret;
 
-	ret = dma_mmap_coherent(NULL, vma, runtime->dma_area,
-			runtime->dma_addr, runtime->dma_bytes);
+	ret = dma_mmap_writecombine(substream->pcm->card->dev, vma,
+		runtime->dma_area, runtime->dma_addr, runtime->dma_bytes);
 
 	pr_debug("%s: ret: %d %p 0x%08x 0x%08x\n", __func__, ret,
 			runtime->dma_area,