Using a temporary subsystem ID, since I haven't found a VGABIOS ROM image for
the PCI version and Bochs doesn't support AGP yet. After modifying Voodoo3.inf
the driver could be installed successfully in Win95/98 and the Voodoo3 works as
expected (same issues as the Banshee model).
Removed BX_ERROR message about setting undocumented srcXY register bits. They
seem to have no effect on the emulation and could be ignored.