linux-phytec-fsl

iommu/vt-d: Avoid duplicate device_domain_info structures

When a 'struct device_domain_info' is created as an alias
for another device, this struct will not be re-used when the
real device is encountered. Fix that to avoid duplicate
device_domain_info structures being added.

Signed-off-by: Joerg Roedel <jroedel@suse.de>