Nouveau will need this on GeForce 8 and up to account for the GPU
reordering physical VRAM for some memory types.
Reviewed-by: NJerome Glisse <jglisse@redhat.com>
Acked-by: NThomas Hellström <thellstrom@vmware.com>
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>