drm/amdgpu/mes: ring aggregatged doorbell when mes queue is unmapped

Ring aggregated doorbel to make unmapped queue scheduled in mes firmware.

Signed-off-by: Le Ma <le.ma@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Jack Xiao <Jack.Xiao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>