sdm: Add LTM support in SDM

-- add LTM related enum and struct into drm interface
-- add LTM properties into DRM property manager and configure LTM
   properties and events in drm_dpps_mgr.
-- add support to allocate ION buffers for LTM histogram during
   dpps initialization if LTM is supported. These ION buffers will
   be deallocated only when DRMDppsManagerImp is out of scope.

Change-Id: I3fcc46ff1256152354d8fcf3cfc67033553b7e5c
5 files changed