Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Remove the BR tag. When the machine doesn't have the DIG64 HCDP
table with console settings, we now only need to know at which
address the UART lives. Leaving the baudrate unspecified results
in us using the baudrate at which the UART operates. This removes
one parameter that can interfere with a successful installation
out of the box.

Remove the last traditional hints. These hints only served the purpose
for uart(4) to figure out which device to use as console. Use this file
to define hw.uart.console instead so that we don't have to put it in
the default loader.conf, which makes it hard to override.

Remove the atkbd, psm, sc and vga devices. Most ia64 boxes out there
are zx1 based machines and they don't particularly like it when we
poke at them with PC legacy code. The atkbd and psm devices were
disabled in the hints file so that one could enable them on machines
that support legacy devices, but that's not really something you can
expect from a first-time installer. This still leaves syscons (sc)
and the vga device, which were enabled by default and wrecking havoc
anyway. We could disable them by default like the atkbd and psm
devices, but there's really no point in pretending we're in a better
shape that way.

MFp4: Revamped GENERIC (and hints). This is some much more pleasant
to look at...

Replace sio(4) with uart(4). Remove the sio(4) hints and only add
those hints used by uart(4) for the determination of the serial
console in the absence of the HCDP table.

Remove mcclock. It's an Alpha left-over.

Make sio0 a console device.

This is the first snapshot of the FreeBSD/ia64 kernel. This kernel will
not work on any real hardware (or fully work on any simulator). Much more
needs to happen before this is actually functional but its nice to see
the FreeBSD copyright message appear in the ia64 simulator.