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>

drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c

@@ -573,6 +573,7 @@ void amdgpu_virt_fini_data_exchange(struct amdgpu_device *adev)
 		DRM_INFO("clean up the vf2pf work item\n");
 		flush_delayed_work(&adev->virt.vf2pf_work);
 		cancel_delayed_work_sync(&adev->virt.vf2pf_work);
+		adev->virt.vf2pf_update_interval_ms = 0;
 	}
 }