drm/amd/display: Add more KUnit tests for amdgpu_dm_ism

[Why & How]
Add 8 more KUnit tests:

- dm_ism_get_idle_allow_delay: add a case where filter_entry_count
  exceeds filter_history_size, exercising the max() branch in the
  history_size calculation.
- amdgpu_dm_ism_init: verify all fields are initialised to
  expected values after construction.
- amdgpu_dm_ism_fini: smoke-test cancellation of never-scheduled
  delayed work items paired with a preceding init.
- dm_ism_set_last_idle_ts: verify last_idle_timestamp_ns is
  updated to at least the value captured before the call.
- dm_ism_insert_record: verify index increment and duration
  calculation; verify out-of-bounds index wraps to slot 0.
- dm_ism_trigger_event: verify current_state and previous_state
  are updated on a valid transition and left unchanged on an
  invalid one.

Assisted-by: Copilot:Claude-Sonnet-4.6
Reviewed-by: Ray Wu <ray.wu@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Ray Wu <ray.wu@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