iommu/fsl: Always allocate a group for non-pci devices

fsl_pamu_device_group() is only called if dev->iommu_group is NULL, so
iommu_group_get() always returns NULL. Remove this test and just allocate
a group. Call generic_device_group() for this like the other drivers.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1-v2-ce71068deeec+4cf6-fsl_rm_groups_jgg@nvidia.com


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