[coreboot] two minor Coreinfo patches

[Myles Watson]

> I notice you removed the checks for < 0 and > something.
>
> I assume these are checked elsewhere?
Yes.  At the end of the file they're checked and forced into bounds.

> Acked-by: Ronald G. Minnich <rminnich at gmail.com>
Rev 4563.

Thanks,
Myles