arm64/mpam: cleanup debuging code

hulk inclusion
category: cleanup
bugzilla: 14389
CVE: NA

Cleanup debuging code for sysreg{read,write}, and {read,write}l.
This code is not compiled in current version, and function changed.

There is no change for md5 checking:
md5sum arch/arm64/kernel/mpam*.o

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