PM / devfreq: add min/max_freq limit requested by users.

The frequency requested to devfreq device driver from devfreq governors
is restricted by min_freq and max_freq input.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
diff --git a/drivers/devfreq/governor_performance.c b/drivers/devfreq/governor_performance.c
index c0596b2..574a06b 100644
--- a/drivers/devfreq/governor_performance.c
+++ b/drivers/devfreq/governor_performance.c
@@ -18,7 +18,10 @@
 	 * target callback should be able to get floor value as
 	 * said in devfreq.h
 	 */
-	*freq = UINT_MAX;
+	if (!df->max_freq)
+		*freq = UINT_MAX;
+	else
+		*freq = df->max_freq;
 	return 0;
 }