ASoC: remove snd_soc_platform_trigger()

No one is using snd_soc_platform_trigger().
Let's remove it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc.h

@@ -507,9 +507,6 @@ int snd_soc_params_to_bclk(struct snd_pcm_hw_params *parms);
 int snd_soc_set_runtime_hwparams(struct snd_pcm_substream *substream,
 	const struct snd_pcm_hardware *hw);
 
-int snd_soc_platform_trigger(struct snd_pcm_substream *substream,
-		int cmd, struct snd_soc_platform *platform);
-
 int soc_dai_hw_params(struct snd_pcm_substream *substream,
 		      struct snd_pcm_hw_params *params,
 		      struct snd_soc_dai *dai);

sound/soc/soc-pcm.c

@@ -2872,15 +2872,6 @@ int snd_soc_dpcm_can_be_params(struct snd_soc_pcm_runtime *fe,
 }
 EXPORT_SYMBOL_GPL(snd_soc_dpcm_can_be_params);
 
-int snd_soc_platform_trigger(struct snd_pcm_substream *substream,
-		int cmd, struct snd_soc_platform *platform)
-{
-	if (platform->driver->ops && platform->driver->ops->trigger)
-		return platform->driver->ops->trigger(substream, cmd);
-	return 0;
-}
-EXPORT_SYMBOL_GPL(snd_soc_platform_trigger);
-
 #ifdef CONFIG_DEBUG_FS
 static const char *dpcm_state_string(enum snd_soc_dpcm_state state)
 {