drm/amd/amdgpu: add fini virt data exchange to ip_suspend

[Why]
when try to shutdown guest vm in sriov mode, virt data
exchange is not fini. After vram lost, trying to write
vram could hang cpu.

[How]
add fini virt data exchange in ip_suspend

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