On suspend, we need to set power gating state to GATE when
VCN5 is busy, otherwise we will get following error on resume:

[drm:amdgpu_ring_test_helper [amdgpu]] *ERROR* ring vcn_unified_0 test failed (-110)
[drm:amdgpu_device_ip_resume_phase2 [amdgpu]] *ERROR* resume of IP block <vcn_v5_0_0> failed -110
amdgpu: amdgpu_device_ip_resume failed (-110).
PM: dpm_run_callback(): pci_pm_resume+0x0/0x100 returns -110
PM: failed to resume async: error -110
Signed-off-by: David (Ming Qiang) Wu <David.Wu3@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>