ASoC: Revert "samsung: Remove unneeded initialization of chan_name"

This reverts commit cdaf9af1ea
which breaks I2S support on the non-DT Samsung SoC platforms,
since the default "tx", "rx" DMA channel names for playback
and capture streams or custom channel names in struct
snd_dmaengine_pcm_config are supported in the ASoC dmaengine
module only for devicetree booting case.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/samsung/dmaengine.c

@@ -37,8 +37,12 @@ int samsung_asoc_dma_platform_register(struct device *dev, dma_filter_fn filter,
 	pcm_conf->prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
 	pcm_conf->compat_filter_fn = filter;
 
-	pcm_conf->chan_names[SNDRV_PCM_STREAM_PLAYBACK] = tx;
-	pcm_conf->chan_names[SNDRV_PCM_STREAM_CAPTURE] = rx;
+	if (dev->of_node) {
+		pcm_conf->chan_names[SNDRV_PCM_STREAM_PLAYBACK] = tx;
+		pcm_conf->chan_names[SNDRV_PCM_STREAM_CAPTURE] = rx;
+	} else {
+		flags |= SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME;
+	}
 
 	return devm_snd_dmaengine_pcm_register(dev, pcm_conf, flags);
 }