drm/amd/display: Test plane color management update

[WHAT]
Add KUnit coverage for the legacy paths of
amdgpu_dm_update_plane_color_mgmt().

Using the shared color-update fixture, the tests cover the bad 3D LUT
size early failure, the default fallback path, implicit CRTC degamma
mapping, color caps taken from the DC context, and a plane CTM mapping to
the DPP gamut remap matrix.

Assisted-by: Copilot:Claude-Opus-4.8 GPT-5.5
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Wayne Lin <wayne.lin@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

0 files changed, 0 insertions, 0 deletions