[coreboot] Coreboot-v2 patch rom names

[Myles Watson]

This patch changes all rom names that aren't coreboot.rom in Config.lb files.

I think that since the directory specifies the architecture and the
board, it is redundant information to name it something else, and it
makes it more difficult to automate the build process (buildrom).

In buildrom we should just use Config-options.lb files instead of
patching or keeping our own.  It just adds more to maintain, with very
little benefit.  The correct place for Config.lb files is in the
coreboot-v2 tree.

The next patch would add Config-lab.lb files for each architecture
supported by buildrom.  Another patch would change buildrom to stop
patching Config.lb files.  There is already a CBV2_CONFIG variable
that would work nicely for selecting the correct file.

Comments?

Signed-off-by: Myles Watson