ASoC: SPEAr: remove custom DMA alloc compat function

spear_pcm_request_chan() is almost identical to
dmaengine_pcm_compat_request_channel(), with the exception that the
latter:

a) Assumes that the DAI DMA data is a struct snd_dmaengine_dai_dma_data
   pointer rather than some custom type.

b) dma_data->filter_data rather than dma_data should be passed to
   snd_dmaengine_pcm_request_channel() as the filter data.

Make minor changes to the SPEAr DAI drivers so that those two conditions
are met. This allows removal of the custom .compat_request_channel().

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/sound/soc/spear/spear_pcm.h b/sound/soc/spear/spear_pcm.h
index 631e2aa..9b0ca62 100644
--- a/sound/soc/spear/spear_pcm.h
+++ b/sound/soc/spear/spear_pcm.h
@@ -17,6 +17,8 @@
 #ifndef __SPEAR_PCM_H__
 #define __SPEAR_PCM_H__
 
-int devm_spear_pcm_platform_register(struct device *dev);
+int devm_spear_pcm_platform_register(struct device *dev,
+			struct snd_dmaengine_pcm_config *config,
+			bool (*filter)(struct dma_chan *chan, void *slave));
 
 #endif