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/tegra30_i2s.h b/sound/soc/tegra/tegra30_i2s.h
index 4d0b0a3..774fc6a 100644
--- a/sound/soc/tegra/tegra30_i2s.h
+++ b/sound/soc/tegra/tegra30_i2s.h
@@ -238,11 +238,14 @@
 	struct clk *clk_i2s;
 	enum tegra30_ahub_txcif capture_i2s_cif;
 	enum tegra30_ahub_rxcif capture_fifo_cif;
+	char capture_dma_chan[8];
 	struct snd_dmaengine_dai_dma_data capture_dma_data;
 	enum tegra30_ahub_rxcif playback_i2s_cif;
 	enum tegra30_ahub_txcif playback_fifo_cif;
+	char playback_dma_chan[8];
 	struct snd_dmaengine_dai_dma_data playback_dma_data;
 	struct regmap *regmap;
+	struct snd_dmaengine_pcm_config dma_config;
 };
 
 #endif