input: qti-haptics: Add input FF driver for QTI haptics

The haptics module in QTI PMICs has the capability to drive both
LRA and ERM actuators which can provide the force feedback for user
actions such as tapping or pressing on the touch screen. Add the
driver to support it and register the haptics as a force-feedback
type input device so that it can be controlled through ioctl/write
APIs on the input device.

Change-Id: I8a9d8dc1d6da40009fc5ab8fbfda205b5e4dd640
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>