mm/sharepool: Fix kabi borken in sp_group_master

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5DS9S


CVE: NA

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The sp_group_master structure is used only in sharepool subsys and no
other drivers use it.

Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>