[media] vivid: use V4L2_DV_FL_IS_CE_VIDEO instead of V4L2_DV_BT_STD_CEA861

Don't rely on V4L2_DV_BT_STD_CEA861 since that include the
640x480p format, which is an IT format, not CE.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>