drm/amdgpu: query the allocated vram address block info

The bad pages that need to be retired are not all allocated
in the same poison consumption process, so an interface is
needed to query the processes that allocate the bad pages.
By killing all the processes that allocate the bad pages,
the bad pages can be reserved immediately.

Signed-off-by: YiPeng Chai <YiPeng.Chai@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>