msm8960-common: introduce opensource lights HAL for AS3676 chips

Originally for hayabusa, but should fit for all phones with
AS3676 LED Controller and the same sysfs interface.
Default control interfaces for Sony blue platform
are defined in lights.cpp. If the phone is using different
set of paths, define TARGET_PROVIDE_CUSTOM_AS3676_SYSFS_PATH
in BoardConfig.mk and define the paths in "sony_lights.h".

Change-Id: I74628609f716167dcbdce13839c977ec16a2ba58