Our current hifn driver (sys/dev/pci/hifn7751.c) doesn't actually do much.

I propose to replace that driver, and replace it with a new driver
ported from OpenBSD circa 3.2 and FreeBSD 4.x. The new driver will
require, (and be available to) the opencrypto framework. This change
will affect users of our current driver, but since the driver doesn't
really do anything, a simple interim solution is to remove the hifn
driver from custom kernel config files until both the new driver and
the crypto framework is completely stable.

I dont have a hifn device myself, but Quentin Garnier has kindly been
doing some remote testing.  We should be able to commit at least
a ``use-at-own-risk'' quality driver in a few days.

There will still be unresolved issues with Hifn's RNG hardware;
more news on that as it comes to hand.