vfio/iommu_type1: Mantain a counter for non_pinned_groups

virt inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I3ZUKK


CVE: NA

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With this counter, we never need to traverse all groups to update
pinned_scope of vfio_iommu.

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Kunkun <Jiang&lt;jiangkunkun@huawei.com>
Reviewed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>