drm/amd/display: Test DSC caps validation

[WHAT]
Add KUnit tests for validate_dsc_caps_on_connector() covering a port
without a DSC AUX channel, the branch AUX workaround, the cascaded
Panamera hub override, a DSC caps read failure and a decoder that does
not advertise DSC.

[HOW]
Attach the absolute DPCD fake to both the root and the port AUX
channels and populate the DSC capability block, then select each path
by tuning the branch descriptor and the topology, and check which AUX
channel is recorded along with the parsed DSC capabilities.

Assisted-by: Copilot:Claude-Opus-5
Reviewed-by: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Chenyu Chen <chen-yu.chen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

0 files changed, 0 insertions, 0 deletions