change guarantees that gfxoff is allowed before moving further in
s2idle sequence to add more reliablity about gfxoff in amdgpu IP's
suspend flow
Signed-off-by: NHarsh Jain <harsh.jain@amd.com>
Reviewed-by: NEvan Quan <evan.quan@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>