iommu/amd: Change amd_iommu_pgtable to use enum protection_domain_mode

Currently it uses enum io_pgtable_fmt which is from the io pagetable code
and most of the enum values are invalid. protection_domain_mode is
internal the driver and has the only two valid values.

Fix some signatures and variables to use the right type as well.

Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v2-9776c53c2966+1c7-amd_paging_flags_jgg@nvidia.com


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