bktr(4) on OpenBSD

The text 69ec054114e4, as OpenBSD 5.3, OpenBSD 5.2, OpenBSD 5.1, OpenBSD 5.0, OpenBSD 4.9, OpenBSD 4.8, OpenBSD 4.7 shipped it.

Brooktree Bt848/849/878/879 PCI TV tuners and video capture boards