virtio-iommu: Remove invalid requirement about padding

This reference to 'padding' is a leftover from a previous draft of the
virtio-iommu device. The field doesn't exist anymore, remove the
requirement.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
1 file changed