powerpc/mm/drconf: Use NUMA_NO_NODE on failures instead of node 0

If we fail to parse the associativity array we should default to
NUMA_NO_NODE instead of NODE 0. Rest of the code fallback to the
right default if we find the numa node value NUMA_NO_NODE.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>