[media] cx231xx: make output mode configurable via the board profile

Extend the board profile structure to allow configuration of the output mode.
Right now they are all doing VIP 1.1 format, but we have a board that needs
ITU656 format (which hasn't been checked in yet).

Signed-off-by: Devin Heitmueller <dheitmueller@hauppauge.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>