nviic(4) on OpenBSD

The text 4a43c0dcf70a, as OpenBSD 5.1, OpenBSD 5.0, OpenBSD 4.9, OpenBSD 4.8, OpenBSD 4.7, OpenBSD 4.6 shipped it.

NVIDIA nForce2/3/4 SMBus controller

nviic(4) on OpenBSD now