iommu/tegra-smmu: Fix client enablement order

Enable clients' translation only after setting up the swgroups.

Signed-off-by: Navneet Kumar <navneetk@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>