media: video-mux: add bayer formats

Add non vendor bayer formats to the allowed format array.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>