mfd: Fix stmpe section mismatch

This fixes:

WARNING: drivers/built-in.o(.text+0xf368f): Section mismatch in reference from
the function stmpe_probe() to the function .devinit.text:stmpe_chip_init()
The function stmpe_probe() references the function __devinit stmpe_chip_init().
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/stmpe.c

@@ -958,7 +958,7 @@ static int __devinit stmpe_devices_init(struct stmpe *stmpe)
 }
 
 /* Called from client specific probe routines */
-int stmpe_probe(struct stmpe_client_info *ci, int partnum)
+int __devinit stmpe_probe(struct stmpe_client_info *ci, int partnum)
 {
 	struct stmpe_platform_data *pdata = dev_get_platdata(ci->dev);
 	struct stmpe *stmpe;