change regulator init function

Move the corresponding function to the right header file and
rename the function with <subsystem>_function_name.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
diff --git a/regulator.c b/regulator.c
index 18c9777..395571b 100644
--- a/regulator.c
+++ b/regulator.c
@@ -15,7 +15,7 @@
 
 #include "regulator.h"
 
-int init_regulator_ds(void)
+int regulator_init(void)
 {
 	DIR *regdir;
 	struct dirent *item;