memcg: Export memcg.high from cgroupv2 to cgroupv1

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4IMAK?from=project-issue


CVE: NA

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Export memory.high from cgroupv2 to cgroupv1. Therefore, when the usage
of the memcg is larger than memory.high, some pages will be reclaimed
before return to userland, which will throttle the process.

Only export memory.high number in mem_cgroup_legacy_files and move
related functions in front of mem_cgroup_legacy_files. There is no need
to other changes.

Signed-off-by: Lu Jialin <lujialin4@huawei.com>
Reviewed-by: weiyang wang <wangweiyang2@huawei.com>
Reviewed-by: weiyang wang <wangweiyang2@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>