regulator: core: Add export of regulator_set_voltage_time_sel()

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index ce0a346..26b7104 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2330,6 +2330,7 @@
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(regulator_set_voltage_time_sel);
 
 /**
  * regulator_sync_voltage - re-apply last regulator output voltage