ASoC: Drop snd_soc_pcm_lib_ioctl()

Now all snd_soc_pcm_lib_ioctl() calls were dropped, and it became
superfluous.  Let's kill it.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20191210145406.21419-24-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc.h

@@ -1399,11 +1399,6 @@ static inline void snd_soc_dapm_mutex_unlock(struct snd_soc_dapm_context *dapm)
 	mutex_unlock(&dapm->card->dapm_mutex);
 }
 
-/* bypass */
-int snd_soc_pcm_lib_ioctl(struct snd_soc_component *component,
-			  struct snd_pcm_substream *substream,
-			  unsigned int cmd, void *arg);
-
 #include <sound/soc-component.h>
 
 #endif