drm/amd/display: correct DML calc error of UrgentLatency

[Why]
The input UrgentLatency in CalculateUrgentBurstFactor
of prefect check is wrong.

[How]
Correct to the correct one to keep same as HW formula

Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Zhongwei <Zhongwei.Zhang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>