As the last step to making groups mandatory, clean up the remaining
drivers by adding basic support. Whilst it may not perfectly reflect
the isolation capabilities of the hardware (tegra_smmu_swgroup sounds
suspiciously like something that might warrant representing at the
iommu_group level), using generic_device_group() should at least
maintain existing behaviour with respect to the API.
Signed-off-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Mikko Perttunen <mperttunen@nvidia.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>