[coreboot] run away pci scan

[Myles Watson]

> I'm working with amd/mahogany_fam10 mainboard and having problems in
> ramstage. It is going through pci device scanning when it starts
> finding the same devices again and malloc memory until it dies. It
> also looks like it never goes down a bridge, always staying on bus0.
> The problem starts at CPU: APIC: 03, it starts scanning bus0 again.
> 
> Anyone have  thoughts on what is happening here? 
Have you tried increasing the stack size?  That's been a problem in the past
with this type of failure.

> Attached complete serial
> log.
I didn't get it.

Thanks,
Myles