drm/amdgpu/gmc8: SRIOV need to program fb location

SRIOV won't do vbios post in guest OS, and the mmMC_VM_FB_LOCATION
is pf and vf copy, so still need to program fb location for SRIOV.

v2: No need to stop mc, and update gmc_v8_0_vram_gtt_location as well.

v3: New line after the stack variables

BUG: SWDEV-126629

Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>