drm/imx/dcss: Add missing of_node_put() in fail path

In dcss_dev_create() and dcss_dev_destroy(), we should call of_node_put()
in fail path or before the dcss's destroy as of_graph_get_port_by_id() has
increased the refcount.

Fixes: 9021c317 ("drm/imx: Add initial support for DCSS on iMX8MQ")
Signed-off-by: Liang He <windhl@126.com>
Reviewed-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220714081337.374761-1-windhl@126.com

drivers/gpu/drm/imx/dcss/dcss-dev.c

@@ -207,6 +207,7 @@ struct dcss_dev *dcss_dev_create(struct device *dev, bool hdmi_output)
 
 	ret = dcss_submodules_init(dcss);
 	if (ret) {
+		of_node_put(dcss->of_port);
 		dev_err(dev, "submodules initialization failed\n");
 		goto clks_err;
 	}
@@ -237,6 +238,8 @@ void dcss_dev_destroy(struct dcss_dev *dcss)
 		dcss_clocks_disable(dcss);
 	}
 
+	of_node_put(dcss->of_port);
+
 	pm_runtime_disable(dcss->dev);
 
 	dcss_submodules_stop(dcss);