Bug#504721: Console broken on debian-installer on Sparc LDOM

I've just tested the committed changes for i386 and s390.

For i386 'console-type' correctly returns "virtual" when booted in 
VirtualBox. I've not tested serial, but am confident that will work as 
well.

On s390 'console-type' returns nothing, which also seems correct as that 
is neither a virtual or serial console, but a dumb console. As we only 
test for '= serial' in reopen-console and everything is properly quoted 
this is no problem. Maybe a test for dumb could be added in the future.

So I'll go ahead and upload the new rootskel.

Cheers,
FJP