Add CMM units to Renesas R-Car Gen3 SoC that support it, and reference them
from the Display Unit they are connected to.

Sort the 'vsps', 'renesas,cmm' and 'status' properties in the DU unit
consistently in all the involved DTS.
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Link: https://lore.kernel.org/r/20191016085548.105703-8-jacopo+renesas@jmondi.orgSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>