platform: msm: add qpnp haptic driver

PMIC devices starting from PMIC8994 support haptic
module. This module operates in four modes - direct,
buffer, pwm and audio.

This module registers with timed_output interface
to interact with user space. It also exposes several
sysfs entries for additional features like dumping
registers, changing play mode... etc.

Change-Id: I26cda875d37af156cfa063a3a18cfa29fad4309a
Signed-off-by: Mohan Pallaka <mpallaka@codeaurora.org>