iommu/amd: Implement global identity domain

Implement global identity domain. All device groups in identity domain
will share this domain.

In attach device path, based on device capability it will allocate per
device domain ID and GCR3 table. So that it can support SVA.

Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20241028093810.5901-11-vasant.hegde@amd.com


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