[coreboot] Atom platform porting problem.

[Myles Watson]

> >> DONE fixed MTRRs
> >> call enable_fixed_mtrr()
> >> Setting variable MTRR 0, base: 0MB, range: 512MB, type WB
> >> ADDRESS_MASK_HIGH=0xf Unexpected Exception: 13 @ 10:001025e9 - Halting
> >> Code: 0 eflags: 00010002
> >> eax: e0000800 ebx: 0000000f ecx: 00000201 edx: 0000000f
> >> edi: e0000000 esi: 00000000 ebp: 0000000f esp: 00139df4
The register contents look like they are from setting the MTRR, so I'd think
the problem was there.

It seems like some processors don't like having too many bits of the MTRRs
set.  I would suggest hacking it so that it doesn't set the upper bits to
see if that makes a difference.

Thanks,
Myles