[media] sh: migor: remove unused ov772x buswidth flag

The ov772x driver only supports 8 bits per sample pixel codes, hence
the OV772X_FLAG_8BIT flag has no effect. Remove it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>