ASoC: soc-dai.c: add .no_capture_mute support

snd_soc_dai_digital_mute() is internally using both
mute_stream() (1) or digital_mute() (2), but the difference between
these 2 are only handling "direction".
We can merge digital_mute() into mute_stream

	int snd_soc_dai_digital_mute(xxx, int direction)
	{
		...
		else if (dai->driver->ops->mute_stream)
(1)			return dai->driver->ops->mute_stream(xxx, direction);
		else if (direction == SNDRV_PCM_STREAM_PLAYBACK &&
			 dai->driver->ops->digital_mute)
(2)			return dai->driver->ops->digital_mute(xxx);
		...
	}

To prepare merging mute_stream()/digital_mute(),
this patch adds .no_capture_mute support to emulate .digital_mute().
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87eeplxxj7.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc-dai.h

@@ -280,6 +280,9 @@ struct snd_soc_dai_ops {
 	 */
 	snd_pcm_sframes_t (*delay)(struct snd_pcm_substream *,
 		struct snd_soc_dai *);
+
+	/* bit field */
+	unsigned int no_capture_mute:1;
 };
 
 struct snd_soc_cdai_ops {

sound/soc/soc-dai.c

@@ -298,8 +298,14 @@ int snd_soc_dai_digital_mute(struct snd_soc_dai *dai, int mute,
 {
 	int ret = -ENOTSUPP;
 
+	/*
+	 * ignore if direction was CAPTURE
+	 * and it had .no_capture_mute flag
+	 */
 	if (dai->driver->ops &&
-	    dai->driver->ops->mute_stream)
+	    dai->driver->ops->mute_stream &&
+	    (direction == SNDRV_PCM_STREAM_PLAYBACK ||
+	     !dai->driver->ops->no_capture_mute))
 		ret = dai->driver->ops->mute_stream(dai, mute, direction);
 	else if (direction == SNDRV_PCM_STREAM_PLAYBACK &&
 		 dai->driver->ops &&