[media] cx231xx: fix NTSC cropcap, add missing cropcap for 417

The pixelaspect ratio was set incorrectly for 60Hz formats.
And since cropcap wasn't implemented at all for the -417 (compressed
video) the pixelaspect was unknown for compressed video.

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