This cuts down on build time, and it will allow libreboot
to remove large chunks of code.

these ifd/gbe configs are just binary-encoded config files,
in a format well-understood. they can easily be opened up
and displayed, using ich9show or ifdtool, and manipulated
by these tools; bincfg can generate them from scratch, and
nvmutil can change mac addresses, for example.

so, do this and remove from lbmk the following:

* ich9utils (which contains ich9gen) - not needed anymore
* code in lbmk for handling ich9gen and insertions; the
  coreboot build system is now used, for this same purpose,
  so remove such code from lbmk

this results in a massive code size reduction (thousands of
lines) in lbmk; smaller when only looking at the build
system, but much larger when you consider that ich9utils
is also removed (about 3k sloc)

Signed-off-by: Leah Rowe <leah@libreboot.org>

don't download it. keep it in lbmk.

libreboot moved to codeberg for git hosting,
and i didn't want to keep lugging around an
extra git repo just for one tiny project.