PM / devfreq: rk3399_dmc: Add missing of_node_put()

of_node_put() needs to be called when the device node which is got
from of_parse_phandle has finished using.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/rk3399_dmc.c

@@ -372,6 +372,7 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
 	node = of_parse_phandle(np, "rockchip,pmu", 0);
 	if (node) {
 		data->regmap_pmu = syscon_node_to_regmap(node);
+		of_node_put(node);
 		if (IS_ERR(data->regmap_pmu))
 			return PTR_ERR(data->regmap_pmu);
 	}