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: I133e8f21fa4ad843219dbefed2d072ad2edab197
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>