sde: Add ScalarHelper class for using Scalar library

Define ScalarHelper class in display engine to communicate with Scalar
library. This class maintains scale data structure and helper funtions.
ResourceManager uses a singleton instance of ScalarHelper to configure
the Scale data structure. HWFrameBuffer uses ScalarHelper to populate
Scale data in mdp_scale_data structure of MDP input layer.

Change-Id: I4008f97dcfd5cf24186f8b4b32a77131c0123a12
10 files changed