drm/amd/display: De PQ implementation

Some refactoring and optimizations in color module.
Added de gamma 2.2 & 2.4, also re gamma 2.2.
Added interface for diagnostic for de gamma & de pq.

Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>