mpu(4) on OpenBSD

The text 0948dea5c2f5, as OpenBSD 4.0, OpenBSD 3.9, OpenBSD 3.8, OpenBSD 3.7, OpenBSD 3.6, OpenBSD 3.5, OpenBSD 3.4 shipped it.

Roland/Yamaha MPU401 (and compatible) MIDI UART driver