Input: add driver support for MAX8997-haptic

The MAX8997-haptic function can be used to control motor. User can
control the haptic driver by using force feedback framework.

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>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>