regulator: export of_get_regulator_init_data

of_get_regulator_init_data is called in drivers/regulator/fixed.c
which could be a module.

Export of_get_regulator_init_data to fix below build error:
ERROR: "of_get_regulator_init_data" [drivers/regulator/fixed.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c
index 76673c78..acd7045 100644
--- a/drivers/regulator/of_regulator.c
+++ b/drivers/regulator/of_regulator.c
@@ -10,6 +10,7 @@
  * (at your option) any later version.
  */
 
+#include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/regulator/machine.h>
@@ -79,3 +80,4 @@
 	of_get_regulation_constraints(dev->of_node, &init_data);
 	return init_data;
 }
+EXPORT_SYMBOL_GPL(of_get_regulator_init_data);