[media] Make use of media bus pixel codes in adv7170 driver

The ADV7170/ADV7171 can operate in either 8-bit or 16-bit YCrCb Mode.

* 8-Bit YCrCb Mode
This default mode accepts multiplexed YCrCb inputs through
the P7-P0 pixel inputs. The inputs follow the sequence Cb0, Y0
Cr0, Y1 Cb1, Y2, etc. The Y, Cb and Cr data are input on a
rising clock edge.

* 16-Bit YCrCb Mode
This mode accepts Y inputs through the P7–P0 pixel inputs and
multiplexed CrCb inputs through the P15–P8 pixel inputs. The
data is loaded on every second rising edge of CLOCK. The inputs
follow the sequence Cb0, Y0 Cr0, Y1 Cb1, Y2, etc.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>