spapr: Populate ibm,associativity-lookup-arrays correctly for non-NUMA

spapr: Populate ibm,associativity-lookup-arrays correctly for non-NUMA

When NUMA isn't configured explicitly, assume node 0 is present for
the purpose of creating ibm,associativity-lookup-arrays property
under ibm,dynamic-reconfiguration-memory DT node. This ensures that
the associativity index property is correctly updated in ibm,dynamic-memory
for the LMB that is hotplugged.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>