LoongArch inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6BWFP

--------------------------------

default to use 40 bits address space for user.
Signed-off-by: NHongchen Zhang <zhanghongchen@loongson.cn>
Change-Id: I23088f43e700ed9b4eb15df2cc9c58299a0582ff