mfd: twl-core: Convert to module_i2c_driver()

Shift TWL initialization to module/device init layer, because I2C now is
not initialized on subsys init layer and shifted to module/device init
layer instead.

The I2C <--> TWL dependency should be resolved in drivers/Makefile now.

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/twl-core.c

@@ -1305,17 +1305,7 @@ static struct i2c_driver twl_driver = {
 	.remove		= twl_remove,
 };
 
-static int __init twl_init(void)
-{
-	return i2c_add_driver(&twl_driver);
-}
-subsys_initcall(twl_init);
-
-static void __exit twl_exit(void)
-{
-	i2c_del_driver(&twl_driver);
-}
-module_exit(twl_exit);
+module_i2c_driver(twl_driver);
 
 MODULE_AUTHOR("Texas Instruments, Inc.");
 MODULE_DESCRIPTION("I2C Core interface for TWL");