opp: core: add regulators enable and disable

Add enable regulators to dev_pm_opp_set_regulators() and disable
regulators to dev_pm_opp_put_regulators(). Even if bootloader
leaves regulators enabled, they should be enabled in kernel in
order to increase the reference count.

Signed-off-by: Kamil Konieczny <[e-mail]>
Signed-off-by: Viresh Kumar <[e-mail]>

drivers/opp/core.c

···
 			goto free_regulators;
 		}
 
+		ret = regulator_enable(reg);
+		if (ret < 0) {
+			regulator_put(reg);
+			goto free_regulators;
+		}
+
 		opp_table->regulators[i] = reg;
 	}
 
···
 	return opp_table;
 
 free_regulators:
-	while (i != 0)
-		regulator_put(opp_table->regulators[--i]);
+	while (i--) {
+		regulator_disable(opp_table->regulators[i]);
+		regulator_put(opp_table->regulators[i]);
+	}
 
 	kfree(opp_table->regulators);
 	opp_table->regulators = NULL;
···
 	/* Make sure there are no concurrent readers while updating opp_table */
 	WARN_ON(!list_empty(&opp_table->opp_list));
 
-	for (i = opp_table->regulator_count - 1; i >= 0; i--)
+	for (i = opp_table->regulator_count - 1; i >= 0; i--) {
+		regulator_disable(opp_table->regulators[i]);
 		regulator_put(opp_table->regulators[i]);
+	}
 
 	_free_set_opp_data(opp_table);