pci: Add a pci-level API for ATS

pci: Add a pci-level API for ATS

Devices implementing ATS can send translation requests using
pci_ats_request_translation. The invalidation events are sent
back to the device using the iommu notifier managed with
pci_iommu_register_iotlb_notifier / pci_iommu_unregister_iotlb_notifier.

Signed-off-by: Clement Mathieu--Drif <clement.mathieu--drif@eviden.com>
Co-authored-by: Ethan Milon <ethan.milon@eviden.com>
Message-Id: <20250520071823.764266-11-clement.mathieu--drif@eviden.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>