[media] bfin_capture: add query_dv_timings/enum_dv_timings support

More dv_timings ioctl ops are introduced in video core.
Add query_dv_timings/enum_dv_timings accordingly.

Signed-off-by: Scott Jiang <scott.jiang.linux@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>