ima: Keep track of the measurment list per ima namespace

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


CVE: NA

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Maintain per ima namespace measurement list. It will be used to provide
information about the namespace measurements in securityfs and to clean up
hash table entries when the namespace is destroyed.

The global measurement list remains and is not modified. It is necessary to
keep it so that the PCR value can be recreated.

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