input: misc: add input driver for HBTP

This driver provides service to Host Based Touch Processing
in three aspects:
- It serves as an input device driver to send touch/key events from
  user space to the kernel input core.
- It monitors LCD on/off and sends uevent accordingly.
- It performs power management for the touch AFE (Analog Front End).

Change-Id: I1308dae8e44a824d84e3b13536a1b621f9df5bca
Signed-off-by: Jing Lin <jinglin@codeaurora.org>