Input: add haptic support for max77843

This patch adds support for haptic on max77843 MFD (Multi Function Device)
with PMIC, MUIC, LED, CHARGER.

This driver supports external pwm and LRA (Linear Resonant Actuator) motor.

Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
[Jim Davis <jim.epost@gmail.com>: should depend on REGULATOR not PWM]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>