lib: utils: Copy over restricted root domain memregions to FDT domains

We should copy over all restricted memregions from the root domain
to the domains populated from FDT. These restricted root memregions
are typically firmware memregion and M-mode only mmio memregions.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>