mfd: Add platform data for MAX8997 MUIC driver

Currently, MAX8997 device does not support MUIC function of it.
To add MAX8997 MUIC driver, header file should be updated.

Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>