iommu/virtio: Build virtio-iommu as module

Now that the infrastructure changes are in place, enable virtio-iommu to
be built as a module. Remove the redundant pci_request_acs() call, since
it's not exported but is already invoked during DMA setup.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/Kconfig

@@ -506,8 +506,8 @@ config HYPERV_IOMMU
 	  guests to run with x2APIC mode enabled.
 
 config VIRTIO_IOMMU
-	bool "Virtio IOMMU driver"
-	depends on VIRTIO=y
+	tristate "Virtio IOMMU driver"
+	depends on VIRTIO
 	depends on ARM64
 	select IOMMU_API
 	select INTERVAL_TREE

drivers/iommu/virtio-iommu.c

@@ -1082,7 +1082,6 @@ static int viommu_probe(struct virtio_device *vdev)
 
 #ifdef CONFIG_PCI
 	if (pci_bus_type.iommu_ops != &viommu_ops) {
-		pci_request_acs();
 		ret = bus_set_iommu(&pci_bus_type, &viommu_ops);
 		if (ret)
 			goto err_unregister;