[coreboot] r820 - in coreboot-v3: mainboard/amd/serengeti southbridge/amd/amd8111

[ron minnich]

it's actually very simple. Stage0 needs to grow -- we might as well
grow to 32768 and see how it goes.

It's also a bug. stage0 code is being truncated to 20480 bytes with on
warning. The pci_find_device function could extend past ffffffff0, but
it gets truncated in the middle -> triple fault.

For now, let's grow to 32768 for stage0. Stefan fixed this so only two
things need to change. Stefan?

ron