PM / devfreq: event: Add const keyword for devfreq_event_ops structure

This patch adds the const keyword for devfreq_event_ops structure
because the ops of devfreq_event_desc structure should not be changed
after initialization.

Cc: Myungjoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

drivers/devfreq/event/exynos-ppmu.c

@@ -194,7 +194,7 @@ static int exynos_ppmu_get_event(struct devfreq_event_dev *edev,
 	return 0;
 }
 
-static struct devfreq_event_ops exynos_ppmu_ops = {
+static const struct devfreq_event_ops exynos_ppmu_ops = {
 	.disable = exynos_ppmu_disable,
 	.set_event = exynos_ppmu_set_event,
 	.get_event = exynos_ppmu_get_event,

include/linux/devfreq-event.h

@@ -91,7 +91,7 @@ struct devfreq_event_desc {
 	const char *name;
 	void *driver_data;
 
-	struct devfreq_event_ops *ops;
+	const struct devfreq_event_ops *ops;
 };
 
 #if defined(CONFIG_PM_DEVFREQ_EVENT)