drm/rcar-du: Configure RGB output routing to DPAD0

The R8A7790 DU variant has a single RGB output called DPAD0 that can be
fed with the output of DU0, DU1 or DU2. Making the routing configurable.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
4 files changed