drm/amdgpu: invalidate parent bo when shadow bo was invalidated

Shadow BO is located on GTT and its parent (PT and PD) BO could located on VRAM.
In some case, the BO on GTT could be evicted but the parent did not. This may
cause the shadow BO not be put in the evict list and could not be invalidate
correctly.
v2: suggested by Christian

Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Reported-by: Shaoyun Liu <Shaoyun.Liu@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>