Merge #1405 into sdk602patch0911 from refs/changes/1405/head

Merge #1405 into sdk602patch0911 from refs/changes/1405/head

fileschecksum.txt check_differential.txt 都统一移动到/user下

* refs/changes/1405/head: (3 commits squashed)

  - fileschecksum.txt check_differential.txt 都统一移动到/user下

  -  fileschecksum.txt check_differential.txt 都统一移动到/user下

  - add AT^POWEROFF

Signed-off-by: snickersun@163.com <accounts_62b90f7fcf51ade33b6f628e@mail.teambition.com>
Reviewed-by: Caisking <3449750381@qq.com>
Reviewed-by: 罗正 <1732036298@qq.com>
Reviewed-by: aliyun8003852482 <1224667075@qq.com>
Reviewed-by: snickersun@163.com <accounts_62b90f7fcf51ade33b6f628e@mail.teambition.com>
Reviewed-by: aliyun6865282430 <1624952103@qq.com>
Merged-by: snickersun@163.com <accounts_62b90f7fcf51ade33b6f628e@mail.teambition.com>
link: https://codeup.aliyun.com/64191456b9581d62e8f81ac0/FD230/change/1405