cy(4) on OpenBSD

The text c91618a81b48, as OpenBSD 4.1, OpenBSD 4.0, OpenBSD 3.9, OpenBSD 3.8, OpenBSD 3.7, OpenBSD 3.6, OpenBSD 3.5 shipped it.

Cyclades Cyclom-{4, 8, 16}Y asynchronous comms board device driver