drm: rcar-du: Support interlaced video output through vsp1

Use the newly exposed VSP1 interface to enable interlaced frame support
through the VSP1 LIF pipelines.

The DSMR register is updated to set the ODEV flag on interlaced
pipelines, thus defining an interlaced stream as having the ODD field
located in the second half (BOTTOM) of the frame buffer.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>