ASoC: generic-dmaengine-pcm: call dma_request_slave_channel()

dma_request_slave_channel() is a more appropriate API for dmaengine
clients that adopt generic DMA bindings to call.  Let's use it instead
of of_dma_request_slave_channel() to save <linux/of_dma.h> include.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/soc-generic-dmaengine-pcm.c

@@ -21,7 +21,6 @@
 #include <sound/soc.h>
 #include <linux/dma-mapping.h>
 #include <linux/of.h>
-#include <linux/of_dma.h>
 
 #include <sound/dmaengine_pcm.h>
 
@@ -219,19 +218,19 @@ static const char * const dmaengine_pcm_dma_channel_names[] = {
 };
 
 static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
-	struct device_node *of_node)
+	struct device *dev)
 {
 	unsigned int i;
 
-	if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || !of_node)
+	if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || !dev->of_node)
 		return;
 
 	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) {
-		pcm->chan[0] = of_dma_request_slave_channel(of_node, "rx-tx");
+		pcm->chan[0] = dma_request_slave_channel(dev, "rx-tx");
 		pcm->chan[1] = pcm->chan[0];
 	} else {
 		for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
-			pcm->chan[i] = of_dma_request_slave_channel(of_node,
+			pcm->chan[i] = dma_request_slave_channel(dev,
 					dmaengine_pcm_dma_channel_names[i]);
 		}
 	}
@@ -255,7 +254,7 @@ int snd_dmaengine_pcm_register(struct device *dev,
 	pcm->config = config;
 	pcm->flags = flags;
 
-	dmaengine_pcm_request_chan_of(pcm, dev->of_node);
+	dmaengine_pcm_request_chan_of(pcm, dev);
 
 	if (flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
 		return snd_soc_add_platform(dev, &pcm->platform,