iommu/amd: Narrow the use of struct protection_domain to invalidation

The AMD io_pgtable stuff doesn't implement the tlb ops callbacks, instead
it invokes the invalidation ops directly on the struct protection_domain.

Narrow the use of struct protection_domain to only those few code paths.
Make everything else properly use struct amd_io_pgtable through the call
chains, which is the correct modular type for an io-pgtable module.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/9-v2-831cdc4d00f3+1a315-amd_iopgtbl_jgg@nvidia.com


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