PM / devfreq: event: Find the instance of devfreq-event device by using phandle

This patch use the phandle to find the instance of devfreq-event device in
Device Tree when calling the devfreq_event_get_edev_by_phandle() because there
is two type devfreq-event devices as following:

First case, exynos-ppmu.c driver provides the maximum four event of each PPMU.
So, when getting the instance of devfreq-event device, using the unique name of
struct devfreq_event_desc.

Second case, exynos-nocp.c driver provide the only one event of each NoC Probe
device. So, when getting the instance of devfreq-event device, using the
phandle of each NoC probe device.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>

drivers/devfreq/devfreq-event.c

@@ -234,6 +234,11 @@ struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(struct device *dev,
 		return ERR_PTR(-ENODEV);
 
 	mutex_lock(&devfreq_event_list_lock);
+	list_for_each_entry(edev, &devfreq_event_list, node) {
+		if (edev->dev.parent && edev->dev.parent->of_node == node)
+			goto out;
+	}
+
 	list_for_each_entry(edev, &devfreq_event_list, node) {
 		if (!strcmp(edev->desc->name, node->name))
 			goto out;