vfio/iommu_type1: Add HWDBM status maintenance

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


CVE: NA

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We are going to optimize dirty log tracking based on iommu dirty
log tracking, but the dirty log from iommu is useful only when
all iommu backed domains support it.

This maintains a counter in vfio_iommu, which is used for dirty
bitmap population in next patch.

This also maintains a boolean flag in vfio_domain, which is used
in the policy of switch dirty log in next patch.

Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
Reviewed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>