ASoC PCM core deals the empty ioctl field now as default.
Let's kill the redundant lines.

Cc: Timur Tabi <timur@kernel.org>
Cc: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: Xiubo Li <Xiubo.Lee@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Link: https://lore.kernel.org/r/20191210145406.21419-7-tiwai@suse.deSigned-off-by: Mark Brown <broonie@kernel.org>