media: vim2m: add bayer capture formats

The vim2m device is interesting to simulate a webcam. As most
sensors are arranged using bayer formats, the best is to support
to output data using those formats.

So, add support for them.

All 4 8-bit bayer formats tested with:

	$ qvidcap -p &
	$ v4l2-ctl --stream-mmap --stream-out-mmap --stream-to-host localhost --stream-lossless --stream-out-hor-speed 1 -v pixelformat=RGGB

It was tested also with GStreamer with:

	$ gst-validate-1.0 filesrc location=some_video.mp4 ! qtdemux ! avdec_h264 ! videoconvert ! videoscale ! v4l2convert disable-passthrough=1 extra-controls="s,horizontal_flip=0,vertical_flip=0" ! bayer2rgb ! videoconvert ! xvimagesink

For all possible HFLIP/VFLIP values.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>