staging: bcm2835-audio: Drop superfluous ioctl PCM ops

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

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20191210141356.18074-5-tiwai@suse.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>