ASoC: samsung: Specify DMA channels through struct snd_dmaengine_pcm_config

The DMA channel names are specified through struct snd_dmaengine_pcm_config
rather than using SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME flag when
booting with devicetree in order to properly support deferred probing.
Without this change the sound machine driver initialization can complete
successfully with unavailable DMA resources.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/samsung/dma.h b/sound/soc/samsung/dma.h
index a7616cc..3830f29 100644
--- a/sound/soc/samsung/dma.h
+++ b/sound/soc/samsung/dma.h
@@ -26,7 +26,10 @@
 void samsung_asoc_init_dma_data(struct snd_soc_dai *dai,
 				struct s3c_dma_params *playback,
 				struct s3c_dma_params *capture);
-int samsung_asoc_dma_platform_register(struct device *dev,
-				       dma_filter_fn fn);
-
+/*
+ * @tx, @rx arguments can be NULL if the DMA channel names are "tx", "rx",
+ * otherwise actual DMA channel names must be passed to this function.
+ */
+int samsung_asoc_dma_platform_register(struct device *dev, dma_filter_fn filter,
+				       const char *tx, const char *rx);
 #endif