gpu: drm: arcpgu_drv: add missing of_node_put after calling of_parse_phandle

of_node_put needs to be called when the device node which is got
from of_parse_phandle has finished using.

Cc: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>

drivers/gpu/drm/arc/arcpgu_drv.c

@@ -127,6 +127,7 @@ static int arcpgu_load(struct drm_device *drm)
 	encoder_node = of_parse_phandle(drm->dev->of_node, "encoder-slave", 0);
 	if (encoder_node) {
 		ret = arcpgu_drm_hdmi_init(drm, encoder_node);
+		of_node_put(encoder_node);
 		if (ret < 0)
 			return ret;
 	} else {