drm/edid: add colorimetry block parsing support

Add support for parsing the colorimetry data block of EDID to get
information about the supported encoding formats of the sink.

This information is needed to use the appropriate color encoding scheme
before transmitting the video stream to the sink.

Change-Id: I1cf9cf75288070ea5a7bd73e15cfbd527199f04c
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>