drm/mediatek: dp: Determine device of next_bridge

It's not necessary to have a next_bridge for DP device, so we add this
patch to judge this.
Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220901044149.16782-8-rex-bc.chen@mediatek.com

drivers/gpu/drm/mediatek/mtk_dp.c

@@ -1886,7 +1886,10 @@ static int mtk_dp_probe(struct platform_device *pdev)
 				     "failed to request dp irq resource\n");
 
 	mtk_dp->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
-	if (IS_ERR(mtk_dp->next_bridge))
+	if (IS_ERR(mtk_dp->next_bridge) &&
+	    PTR_ERR(mtk_dp->next_bridge) == -ENODEV)
+		mtk_dp->next_bridge = NULL;
+	else if (IS_ERR(mtk_dp->next_bridge))
 		return dev_err_probe(dev, PTR_ERR(mtk_dp->next_bridge),
 				     "Failed to get bridge\n");