Some small cleanups and when setting the frequency it is now clamped
to the valid frequency range instead of returning an error.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Fabio Belavenuto <belavenuto@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>