MIPS: Loongson: Modify ChipConfig register definition

This patch is prepared for Multi-chip interconnection. Since each chip
has a ChipConfig register, LOONGSON_CHIPCFG should be an array.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/7185/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>