ASoC: tegra: convert to standard DMA DT bindings

By passing no flags when calling snd_dmaengine_pcm_register() from
tegra_pcm.c, we end up using dma_request_slave_channel() rather than
dmaengine_pcm_compat_request_channel(), and hence rely on the standard
DMA DT bindings and stashing the DMA slave ID away during channel
allocation. This means there's no need to use a custom DT property to
store the slave ID. So, remove all the code that parsed it.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Mark Brown <broonie@linaro.org>
diff --git a/sound/soc/tegra/tegra_pcm.h b/sound/soc/tegra/tegra_pcm.h
index 68ad901..7883dec 100644
--- a/sound/soc/tegra/tegra_pcm.h
+++ b/sound/soc/tegra/tegra_pcm.h
@@ -31,7 +31,12 @@
 #ifndef __TEGRA_PCM_H__
 #define __TEGRA_PCM_H__
 
+struct snd_dmaengine_pcm_config;
+
 int tegra_pcm_platform_register(struct device *dev);
+int tegra_pcm_platform_register_with_chan_names(struct device *dev,
+				struct snd_dmaengine_pcm_config *config,
+				char *txdmachan, char *rxdmachan);
 void tegra_pcm_platform_unregister(struct device *dev);
 
 #endif