x86, VisWS: turn into generic arch, make VisWS boot on a regular PC

first step: make the VISWS subarch boot on a regular PC.

We take various shortcuts for that. We copy the generic arch setup file over
into the VISWS setup file.

This is the only step that is not expected to boot on a real VISWS.

Signed-off-by: Ingo Molnar <mingo@elte.hu>