drm/amdgpu: partial revert cleanup setting bulk_movable v2

We still need to set bulk_movable to false when new BOs are added or removed.

v2: also set it to false on removal

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: StDenis, Tom <Tom.StDenis@amd.com>
Tested-by: Przemek Socha <soprwa@gmail.com>
Reviewed-by: Zhou, David(ChunMing) <David1.Zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>