spapr: Revert to memory@XXXX representation for non-hotplugged memory

spapr: Revert to memory@XXXX representation for non-hotplugged memory

Don't represent non-hotluggable memory under drconf node. With this
we don't have to create DRC objects for them.

The effect of this patch is that we revert back to memory@XXXX representation
for all the memory specified with -m option and represent the cold
plugged memory and hot-pluggable memory under
ibm,dynamic-reconfiguration-memory.

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>