drm/amdgpu: Remove programming GCMC_VM_FB_LOCATION* on gfxhub_v3_0_3 in VF

[Why]
GCMC_VM related registers should be programmed by PSP on host side.
L1 and RLCG will block these regisers on VF.

[How]
Remove programming GCMC_VM_FB_LOCATION_BASE/TOP on gfxhub_v3_0_3 under SRIOV VF.

Signed-off-by: Yifan Zha <Yifan.Zha@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>