mfd: Fix twl_probe section mismatch warning in mfd/twl-core.c

Fix the following section mismatch warning when building
omap2plus_defconfig:

WARNING: vmlinux.o(.data+0x47d7c): Section mismatch in reference
from the variable twl_driver to the function .init.text:twl_probe()

Signed-off-by: Bryan Wu <[e-mail]>
Signed-off-by: Paul Walmsley <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/mfd/twl-core.c

···
 }
 
 /* NOTE:  this driver only handles a single twl4030/tps659x0 chip */
-static int __init
+static int __devinit
 twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	int				status;