[media] davinci: vpif_capture: drop compliance hack

Capture driver silently overrides pixel format with a hack (according to
the comments) to pass v4l2 compliance tests.  This isn't needed for
normal functionality, and works for composite video and raw camera capture
without.

In addition, the hack assumes that it only supports raw capture with a
single format (SBGGR8) which isn't true.  VPIF can also capture 10- and
12-bit raw formats as well.  Forthcoming patches will enable VPIF
input with raw-camera support and has been tested with 10-bit format
from the aptina,mt9v032 sensor.

Any compliance failures should be fixed with a real fix.

Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>