drm: rcar-du: Implement support for interlaced modes

Accept interlaced modes on the VGA and HDMI connectors and configure the
hardware accordingly.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_hdmicon.c b/drivers/gpu/drm/rcar-du/rcar_du_hdmicon.c
index 322b720..ca94b02 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_hdmicon.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_hdmicon.c
@@ -95,6 +95,7 @@
 	connector = &rcon->connector;
 	connector->display_info.width_mm = 0;
 	connector->display_info.height_mm = 0;
+	connector->interlace_allowed = true;
 	connector->polled = DRM_CONNECTOR_POLL_HPD;
 
 	ret = drm_connector_init(rcdu->ddev, connector, &connector_funcs,