Revert "svm: Add svm_set_user_mpam_en to enable/disable mpam for smmu"

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


CVE: NA

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This reverts commit c50ad40d.
The commit "svm: Add svm_set_user_mpam_en to enable/disable mpam for smmu"
add and export interface in svm module, this makes the mpam depend on
the svm module, just revert this to avoid coupling.

Signed-off-by: Xingang Wang <wangxingang5@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>