drm: rcar-du: dw-hdmi: Set output port number

Report the DT output port number in dw_hdmi_plat_data to connect to the
next bridge in the dw-hdmi driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com> # On V3U
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

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

@@ -75,6 +75,7 @@ static int rcar_hdmi_phy_configure(struct dw_hdmi *hdmi, void *data,
 }
 
 static const struct dw_hdmi_plat_data rcar_dw_hdmi_plat_data = {
+	.output_port = 1,
 	.mode_valid = rcar_hdmi_mode_valid,
 	.configure_phy	= rcar_hdmi_phy_configure,
 };