drm/amd/display: add DMUB command sync KUnit coverage

[WHAT]
Add KUnit coverage for the synchronous DMUB command helpers:
dm_execute_dmub_cmd(), amdgpu_dm_process_dmub_aux_transfer_sync(), and
amdgpu_dm_process_dmub_set_config_sync(). Cover command submission
without a DC DMUB service, AUX engine-acquire failure, protocol-error
propagation, the bounded reply-data copy, the zero-length reply branch,
and the SET_CONFIG completed-with-unknown-error path.

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