drm/amdgpu/mes12: correct kiq unmap latency

Correct kiq unmap queue timeout value.

Signed-off-by: Jack Xiao <Jack.Xiao@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit cfe98204)
Cc: stable@vger.kernel.org # 6.11.x