PM / devfreq: shut up kernel-doc warnings

There are 4 warnings there:
	drivers/devfreq/devfreq.c:707: warning: Function parameter or member 'val' not described in 'qos_min_notifier_call'
	drivers/devfreq/devfreq.c:707: warning: Function parameter or member 'ptr' not described in 'qos_min_notifier_call'
	drivers/devfreq/devfreq.c:717: warning: Function parameter or member 'val' not described in 'qos_max_notifier_call'
	drivers/devfreq/devfreq.c:717: warning: Function parameter or member 'ptr' not described in 'qos_max_notifier_call'

It turns that neither val nor ptr are actually used on those
function, so document as such.
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/devfreq.c

@@ -696,6 +696,8 @@ static int qos_notifier_call(struct devfreq *devfreq)
 /**
  * qos_min_notifier_call() - Callback for QoS min_freq changes.
  * @nb:		Should be devfreq->nb_min
+ * @val:	not used
+ * @ptr:	not used
  */
 static int qos_min_notifier_call(struct notifier_block *nb,
 					 unsigned long val, void *ptr)
@@ -706,6 +708,8 @@ static int qos_min_notifier_call(struct notifier_block *nb,
 /**
  * qos_max_notifier_call() - Callback for QoS max_freq changes.
  * @nb:		Should be devfreq->nb_max
+ * @val:	not used
+ * @ptr:	not used
  */
 static int qos_max_notifier_call(struct notifier_block *nb,
 					 unsigned long val, void *ptr)