xen/arm: don't pass iommu properties to hwdom for iommu-map

A device tree node for a PCIe root controller may have an iommu-map property [1]
with a phandle reference to the SMMU node, but not necessarily an iommus
property. In this case, we want to treat it the same as we currently handle
devices with an iommus property: don't pass the iommu related properties to
hwdom.

[1] https://www.kernel.org/doc/Documentation/devicetree/bindings/pci/pci-iommu.txt

Reported-by: Michal Orzel <michal.orzel@amd.com>
Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
Acked-by: Julien Grall <jgrall@amazon.com>

xen/arch/arm/domain_build.c

@@ -550,6 +550,8 @@ static int __init write_properties(struct domain *d, struct kernel_info *kinfo,
      * should be skipped.
      */
     iommu_node = dt_parse_phandle(node, "iommus", 0);
+    if ( !iommu_node )
+        iommu_node = dt_parse_phandle(node, "iommu-map", 1);
     if ( iommu_node && device_get_class(iommu_node) != DEVICE_IOMMU )
         iommu_node = NULL;