drm: rcar-du: Don't select VSP1 sink on Gen3

The VSP1 sink selection through register DEFR8 is only available on Gen2
hardware. Skip it on Gen3.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

drivers/gpu/drm/rcar-du/rcar_du_plane.c

@@ -549,7 +549,9 @@ void __rcar_du_plane_setup(struct rcar_du_group *rgrp,
 		rcar_du_plane_setup_format(rgrp, (state->hwindex + 1) % 8,
 					   state);
 
-	if (rcdu->info->gen < 3)
+	if (rcdu->info->gen >= 3)
+		return;
+
 	rcar_du_plane_setup_scanout(rgrp, state);
 
 	if (state->source == RCAR_DU_PLANE_VSPD1) {