regulator: core: Stub devm_regulator_bulk_get_const() if !CONFIG_REGULATOR

When adding devm_regulator_bulk_get_const() I missed adding a stub for
when CONFIG_REGULATOR is not enabled. Under certain conditions (like
randconfig testing) this can cause the compiler to reports errors
like:

  error: implicit declaration of function 'devm_regulator_bulk_get_const';
  did you mean 'devm_regulator_bulk_get_enable'?

Add the stub.

Fixes: 1de452a0 ("regulator: core: Allow drivers to define their init data as const")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202408301813.TesFuSbh-lkp@intel.com/
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20240830073511.1.Ib733229a8a19fad8179213c05e1af01b51e42328@changeidSigned-off-by: Mark Brown <broonie@kernel.org>

include/linux/regulator/consumer.h

@@ -452,6 +452,14 @@ static inline int of_regulator_bulk_get_all(struct device *dev, struct device_no
 	return 0;
 }
 
+static inline int devm_regulator_bulk_get_const(
+	struct device *dev, int num_consumers,
+	const struct regulator_bulk_data *in_consumers,
+	struct regulator_bulk_data **out_consumers)
+{
+	return 0;
+}
+
 static inline int regulator_bulk_enable(int num_consumers,
 					struct regulator_bulk_data *consumers)
 {