s_std didn't belong in the tuner ops. Stricly speaking it should be part of
the video ops, but it is used by audio and tuner devices as well, so it is
more efficient to make it part of the core ops.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>