Extend the SMI with switch (intermediate hop) support. Care has been
taken to ensure that the CA (and router) code paths are changed as
little as possible.
Signed-off-by: Suresh Shelvapille <suri@baymicrosystems.com> Signed-off-by: Hal Rosenstock <halr@voltaire.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>