arm64/mpam: operation not permitted when remove a ctrl group with a mondata

hulk inclusion
category: feature
feature: ARM MPAM support
bugzilla: 48265
CVE: NA

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root@(none)$ ls
cpus        cpus_list   ctrlmon     mon_data    mon_groups  schemata    tasks
root@(none)$ cd ../
root@(none)$ rmdir p2
rmdir: 'p2': Operation not permitted

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>