There is no device node for the empty NUMA node. However, the
corresponding NUMA node ID and distance map is still valid in
"numa-distance-map-v1" compatible device node.

This fetches the NUMA node ID and distance map for these empty
NUMA node from "numa-distance-map-v1" compatible device node.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20210927064119.127285-3-gshan@redhat.comSigned-off-by: Rob Herring <robh@kernel.org>