[coreboot] Failover images

[Myles Watson]

I've never understood the need for failover images.  Why wouldn't we just
have a shell for the fallback payload?  I saw a comment in the code
somewhere that failover should go away.  Will it?

I've never gotten failover to work with Tyan s2895.  It compiles fine but
won't boot.

Thanks,
Myles