NUMA enabled kernel on FDT based machine fails to boot because CPUs
are all in NUMA_NO_NODE and mm subsystem won't accept that.

Fix by adding them to default NUMA node at FDT parsing phase and move
numa_add_cpu(0) to a later point.

Cc: stable@vger.kernel.org
Fixes: 88d4d957 ("LoongArch: Add FDT booting support from efi system table")
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>