drm/amdgpu: enable pdb0 for hibernation on SRIOV

When switching to new GPU index after hibernation and then resume,
VRAM offset of each VRAM BO will be changed, and the cached gpu
addresses needed to updated.

This is to enable pdb0 and switch to use pdb0-based virtual gpu
address by default in amdgpu_bo_create_reserved(). since the virtual
addresses do not change, this can avoid the need to update all
cached gpu addresses all over the codebase.

Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Signed-off-by: Samuel Zhang <guoqing.zhang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>