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

(*) commit fc033cbf ("ALSA: pcm: Allow NULL ioctl ops")

Link: https://lore.kernel.org/r/20191210061145.24641-19-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>