[media] staging/media: fix querycap

Querycap shouldn't set the version field (the core does that for you),
but it should set the device_caps field.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>