sdm: Add support to pass HDR metadata to HDR External Displays

HDR metadata needs to be passed to the HDR Displays which are
connected thru HDMI or DP Interfaces.
This changes adds support for passing that information
to the such displays.

Change-Id: Iae2778eb9914848d3d197cfd75c9d07381994eec
Crs-fixed: 1109274
3 files changed