drm/amdgpu: Create VRAM BOs on GTT for GFXIP9.4.3

On GFXIP9.4.3 APP APU where there is no dedicated VRAM domain handle
VRAM BO allocation requests on CPU domain and validate them on GTT.

Support for handling multi-socket and multi-numa partitions within a
socket will be added by future patches, this enables 1P NPS1 asic
bringup configuration.

Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>