arm64/mpam: add cmdline option: mpam

hulk inclusion
category: feature
bugzilla: 10897
CVE: NA

MPAM feature is just for debug and preview in this version,
so disable it by default. You can enable it by cmdline: "mpam".

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>