svm: Add support to get svm mpam configuration

ascend inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I49RB2


CVE: NA

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This add interface to get mpam configuration of accelarators managed
by svm. The svm mpam get interface traverse all accelrators, and if
all succeed, return the last successful result.

Signed-off-by: Xingang Wang <wangxingang5@huawei.com>
Reviewed-by: Yingtai Xie <xieyingtai@huawei.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>