This also uncouples cbfstool from being overly Chromium
specific. However the main objective is to not subprocess
flashrom any more and instead use the programmatic API.
BUG=b:207808292
TEST=built and ran `elogtool (list|clear|add 0x16 C0FFEE)`.
Change-Id: I79df2934b9b0492a554a4fecdd533a0abe1df231
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59714
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sam McNally <sammc@google.com>
