iommu/of: Use -ENODEV consistently in of_iommu_configure()

Instead of returning 1 and trying to handle positive error codes just
stick to the convention of returning -ENODEV. Remove references to ops
from of_iommu_configure(), a NULL ops will already generate an error code.

There is no reason to check dev->bus, if err=0 at this point then the
called configure functions thought there was an iommu and we should try to
probe it. Remove it.

Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Moritz Fischer <moritzf@google.com>
Tested-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v2-16e4def25ebb+820-iommu_fwspec_p1_jgg@nvidia.com


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