GART can't handle all devices, hence ignore devices that aren't related
to GART. IOMMU phandle must be explicitly assign to devices in the device
tree.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>