MIPS: Fix a typo error in AUDIT_ARCH definition

Missing a "|" in AUDIT_ARCH_MIPSEL64N32 macro definition.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.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/6978/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>