iommu/dart: Convert to domain_alloc_paging()

Since the IDENTITY and BLOCKED behaviors were moved to global statics all
that remains is the paging domain. Rename to
apple_dart_attach_dev_paging() and remove the left over type check.

Reviewed-by: Janne Grunau <j@jannau.net>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Sven Peter <sven@svenpeter.dev>
Link: https://lore.kernel.org/r/7-v2-bff223cf6409+282-dart_paging_jgg@nvidia.com


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