ima: Add ima namespace id to the measurement list related structures

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I49KW1


CVE: NA

--------------------------------

Add ima namespace id to the ima_event_data and ima_template_entry. This is
done so that the template entries can be tracked per ima namespace. The
following patches will add new templates that will include the namespace
id, but the namespace id has to be stored separately so that the namespace
functionality is enabled for every template.

After kexec, all entries from the old measurement list will be associated
with the new root ima namespace. This will prevent users in the new ima
namespaces from accessing the old entries if the ima namespace id is
reused.

Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Reviewed-by: Zhang Tianxing <zhangtianxing3@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>