opp: Staticize _add_opp_table()

_add_opp_table() isn't used outside of core.c, mark it static.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/opp/core.c

@@ -1193,7 +1193,7 @@ struct opp_table *_add_opp_table_indexed(struct device *dev, int index)
 	return opp_table;
 }
 
-struct opp_table *_add_opp_table(struct device *dev)
+static struct opp_table *_add_opp_table(struct device *dev)
 {
 	return _add_opp_table_indexed(dev, 0);
 }

drivers/opp/opp.h

@@ -223,7 +223,6 @@ int _opp_compare_key(struct dev_pm_opp *opp1, struct dev_pm_opp *opp2);
 int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table, bool rate_not_available);
 int _opp_add_v1(struct opp_table *opp_table, struct device *dev, unsigned long freq, long u_volt, bool dynamic);
 void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, int last_cpu);
-struct opp_table *_add_opp_table(struct device *dev);
 struct opp_table *_add_opp_table_indexed(struct device *dev, int index);
 void _put_opp_list_kref(struct opp_table *opp_table);