TNT5004 IC. This involved a major rewrite of a number of things, as
this chip no longer supports the NAT7210 legacy mode but requires the
host to use the (more modern) FIFO mode.
In theory, this also ought to work on the older TNT4882C chip. I'll
probably add this as optional support (perhaps by a device.hints flag)
later on. By now, FIFO mode is *only* activates iff a TNT5004 chip
has been detected (where the old code didn't work at all), while
everything else is supposed to use the old code.
MFC after: 2 weeks
frontend uses the same uPD7210 backend as the pcii ISA frontend, so
the backend has to cope with both situations.
Also, hide the first printf in pcii_probe (address mismatch) behind
bootverbose as the ISA bus parent tries to probe all configured ISA
devices against each driver, so a the console has been cluttered with
this message for a bunch of unrelated driver probes.
MFC after: 3 days
