Rather than have a group where some items behave differently than
others, configfs provides a method whereby one or many subgroups are
automatically created inside the parent at its creation. Thus,
-mkdir("parent) results in "parent", "parent/subgroup1", up through
+mkdir("parent") results in "parent", "parent/subgroup1", up through
"parent/subgroupN". Items of type 1 can now be created in
"parent/subgroup1", and items of type N can be created in
"parent/subgroupN".