Shashank Sharma authored Apr 22, 2019 and Harish Krupo committed Jun 19, 2019

This patch is the first patch of HDR metadata enabling series
for drm-compositor. It does the following:
- Defines a new data structure to capture display's HDR metadata
  related information from its EDID.
- Places this new data structures in drm-head.
- Adds a new file, which contains functions to parse EDID's CEA
  extension block and extract static HDR metadata data (CEA-861-G).
- While parsing EDID, parses hdr-metadata and saves into drm-head.

V2: Addressed review comments from Pekka

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>