regulator: Add empty devm_regulator_bulk_get for !CONFIG_REGULATOR

This fixes below build error if CONFIG_REGULATOR is disabled.

  CC      sound/soc/codecs/wm5100.o
sound/soc/codecs/wm5100.c: In function ‘wm5100_i2c_probe’:
sound/soc/codecs/wm5100.c:2462: error: implicit declaration of function ‘devm_regulator_bulk_get’
make[3]: *** [sound/soc/codecs/wm5100.o] Error 1
make[2]: *** [sound/soc/codecs] Error 2
make[1]: *** [sound/soc] Error 2
make: *** [sound] Error 2

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/linux/regulator/consumer.h

@@ -249,6 +249,12 @@ static inline int regulator_bulk_get(struct device *dev,
 	return 0;
 }
 
+static inline int devm_regulator_bulk_get(struct device *dev, int num_consumers,
+					  struct regulator_bulk_data *consumers)
+{
+	return 0;
+}
+
 static inline int regulator_bulk_enable(int num_consumers,
 					struct regulator_bulk_data *consumers)
 {