iommufd/selftest: Add test ops to test pasid attach/detach

This adds 4 test ops for pasid attach/replace/detach testing. There are
ops to attach/detach pasid, and also op to check the attached hwpt of a
pasid.

Link: https://patch.msgid.link/r/20250321171940.7213-18-yi.l.liu@intel.com


Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>