drm/amd/display: Fix the Wunused-function warning

drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:941:13: warning: ‘dm_dmub_trace_high_irq’ defined but not used [-Wunused-function]
  941 | static void dm_dmub_trace_high_irq(void *interrupt_params)
      |             ^~~~~~~~~~~~~~~~~~~~~~

Fixes: a08f16cf ("drm/amd/display: Log DMCUB trace buffer events")
Cc: Leo (Hanghong) Ma <hanghong.ma@amd.com>
Cc: Daniel Wheeler <daniel.wheeler@amd.com>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Cc: Solomon Chiu <solomon.chiu@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>