hw/hppa: Disable Artist graphics card on 64-bit machines

The original Artist graphics used the GSC bus, was often installed in old
32-bit machines (e.g. 715) and can not be used on 64-bit machines.
This is why this patch makes the artist driver dependend on the Lasi chip,
which was never used in a 64-bit machine.

Note that there exists a variant of Artist for the PCI-bus (Visualize-EG PCI).
It has quite some differences in the registers, and would require that we write
a PCI ROM for it, so that Linux and HP-UX would be able to use it.

Instead, for now, users can simply use a standard VGA or ATI PCI graphics card
on Linux.  This can be enabled on the command line with "-device ati-vga" or
"-device VGA".  If the "-nographic" option is omitted, a PCI OCHI controller
with USB keyboard and USB mouse will be added automatically.

This fixes graphics support on 64-bit hppa machines and allows us to boot up a
64-bit Linux installation with VGA graphics.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20260330211859.19317-3-deller@kernel.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>