ASoC: soc-pcm: remove soc_rtdcom_ack()

No ALSA SoC driver has .ack at component->driver->ops.
We can revive it if some-driver want to use it, but let's remove it
so far to avoid maintaining complex code
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87muh15roz.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-pcm.c

@@ -2873,26 +2873,6 @@ static void soc_pcm_private_free(struct snd_pcm *pcm)
 	}
 }
 
-static int soc_rtdcom_ack(struct snd_pcm_substream *substream)
-{
-	struct snd_soc_pcm_runtime *rtd = substream->private_data;
-	struct snd_soc_rtdcom_list *rtdcom;
-	struct snd_soc_component *component;
-
-	for_each_rtdcom(rtd, rtdcom) {
-		component = rtdcom->component;
-
-		if (!component->driver->ops ||
-		    !component->driver->ops->ack)
-			continue;
-
-		/* FIXME. it returns 1st ask now */
-		return component->driver->ops->ack(substream);
-	}
-
-	return -EINVAL;
-}
-
 static int soc_rtdcom_copy_user(struct snd_pcm_substream *substream, int channel,
 				unsigned long pos, void __user *buf,
 				unsigned long bytes)
@@ -3129,8 +3109,6 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
 		if (!ops)
 			continue;
 
-		if (ops->ack)
-			rtd->ops.ack		= soc_rtdcom_ack;
 		if (ops->copy_user)
 			rtd->ops.copy_user	= soc_rtdcom_copy_user;
 		if (ops->copy_kernel)