PM / OPP: export dev_pm_opp_get_notifier

Allows user drivers such as devfreq to be modules.
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/power/opp.c

@@ -742,6 +742,7 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev)
 
 	return &dev_opp->srcu_head;
 }
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_notifier);
 
 #ifdef CONFIG_OF
 /**