iommu: add iommu interface to set/get device configuration

ascend inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4L735


CVE: NA

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This introduce support to set and get device configuration in iommu
private driver. For example, when the smmu mpam configuration need to be
set in the smmu driver, these interfaces will help.

Signed-off-by: Xingang Wang <wangxingang5@huawei.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>