vfio/spapr: Relax the IOMMU compatibility check

We are going to have multiple different types of PHB on the same system
with POWER8 + NVLink and PHBs will have different IOMMU ops. However
we only really care about one callback - create_table - so we can
relax the compatibility check here.
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Acked-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

drivers/vfio/vfio_iommu_spapr_tce.c

@@ -1188,7 +1188,8 @@ static int tce_iommu_attach_group(void *iommu_data,
 			goto unlock_exit;
 		}
 		table_group_tmp = iommu_group_get_iommudata(tcegrp->grp);
-		if (table_group_tmp->ops != table_group->ops) {
+		if (table_group_tmp->ops->create_table !=
+				table_group->ops->create_table) {
 			pr_warn("tce_vfio: Group %d is incompatible with group %d\n",
 					iommu_group_id(iommu_group),
 					iommu_group_id(tcegrp->grp));