regulator: core: Fix exported symbols to the exported GPL version

Change the exported symbols introduced by commit e915331
("regulator: vctrl-regulator: Avoid deadlock getting and setting the voltage")
from EXPORT_SYMBOL() to EXPORT_SYMBOL_GPL(), like is used for all the core
parts.

Fixes: e915331 ("regulator: vctrl-regulator: Avoid deadlock getting and setting the voltage")
Reported-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20200120123921.1204339-1-enric.balletbo@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/core.c

@@ -3466,7 +3466,7 @@ int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV,
 out:
 	return ret;
 }
-EXPORT_SYMBOL(regulator_set_voltage_rdev);
+EXPORT_SYMBOL_GPL(regulator_set_voltage_rdev);
 
 static int regulator_limit_voltage_step(struct regulator_dev *rdev,
 					int *current_uV, int *min_uV)
@@ -4031,7 +4031,7 @@ int regulator_get_voltage_rdev(struct regulator_dev *rdev)
 		return ret;
 	return ret - rdev->constraints->uV_offset;
 }
-EXPORT_SYMBOL(regulator_get_voltage_rdev);
+EXPORT_SYMBOL_GPL(regulator_get_voltage_rdev);
 
 /**
  * regulator_get_voltage - get regulator output voltage