media: v4l: mediabus: Recognise CSI-2 D-PHY and C-PHY

The CSI-2 bus may use either D-PHY or C-PHY. Make this visible in media
bus enum.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>