vfio/iommufd: Implement VFIOIOMMUClass::set_dirty_tracking support

vfio/iommufd: Implement VFIOIOMMUClass::set_dirty_tracking support

ioctl(iommufd, IOMMU_HWPT_SET_DIRTY_TRACKING, arg) is the UAPI that
enables or disables dirty page tracking. The ioctl is used if the hwpt
has been created with dirty tracking supported domain (stored in
hwpt::flags) and it is called on the whole list of iommu domains.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>