linux-phytec-fsl

iommu/fsl: Fix the device domain attach condition.

Store the domain information for the device, only if it's not already
attached to a domain.

Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>