[media] msi2500: change supported formats

Enable two native formats, V4L2_SDR_FMT_CS8 and V4L2_SDR_FMT_CS14LE.
Move emulated formats behind module parameter.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>