drm/amdgpu/sriov Stop data exchange for wholegpu reset

[Why]
When host trigger a whole gpu reset, guest will keep
waiting till host finish reset. But there's a work
queue in guest exchanging data between vf&pf which need
to access frame buffer. During whole gpu reset, frame
buffer is not accessable, and this causes the call trace.

[How]
After vf get reset notification from pf, stop data exchange.

Signed-off-by: Jingwen Chen <Jingwen.Chen2@amd.com>
Signed-off-by: Jack Zhang <Jack.Zhang1@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>