Pekka Paalanen authored May 06, 2022 and Pekka Paalanen committed May 27, 2022

Output color profile may be changed in flight. Output basic color
characteristics and EOTF mode cannot yet be changed in flight, but it is
reasonable to assume they could in the future. Therefore the color
outcome data may change in flight as well, which is the basis for HDR
metadata, which needs to be updated as well.

Track the changes to color outcome data with a serial number.
DRM-backend checks the serial number to see if it needs to re-create the
HDR metadata blob. This allows the changes to propagate all the way to
KMS.

The code added here is more of a reminder of what should happen than a
tested path.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>