[libvirt_manager] Allow for virtualized pci passthrough

[jamepark4]

To allow for a virtualized compute to passthrough its devices to the emulated guests the compute needs to have iommu device present. If pci_passthrough_enabled is present and true add device element to VM XML.

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❌ openstack-k8s-operators-content-provider FAILURE in 7m 44s
⚠️ podified-multinode-edpm-deployment-crc SKIPPED Skipped due to failed job openstack-k8s-operators-content-provider
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⚠️ cifmw-crc-podified-edpm-baremetal-minor-update SKIPPED Skipped due to failed job openstack-k8s-operators-content-provider
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❌ cifmw-molecule-libvirt_manager FAILURE in 10m 53s
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