pseries: Move adding of fdt reserve map entries

pseries: Move adding of fdt reserve map entries

The flattened device tree passed to pseries guests contains a list of
reserved memory areas.  Currently we construct this list early in
spapr_create_fdt_skel() as we sequentially write the fdt.

This will be inconvenient for upcoming cleanups, so this patch moves
the reserve map changes to the end of fdt construction.  This changes
fdt_add_reservemap_entry() calls - which work when writing the fdt
sequentially to fdt_add_mem_rsv() calls used when altering the fdt in
random access mode.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com>