[coreboot] What is the best way to treat warnings reported by checkpatch.pl

[Julius Werner]

> The point is, that without ((packed)) there is no guarantee that gcc
> won't choose a different alignment over what you and I think would make
> sense.

In practice it is very predictable and there should be no sane reason
to do it otherwise. Like with many of the other "it's not guaranteed
in the standard but GCC and Clang have been doing it this way since
forever" issues where being standards-compliant would incur a serious
performance or readability hit, I'd advocate being pragmatic. Everyone
knows the standard is stupid, but we still need to generate the
binaries we want somehow. (And, of course, __attribute__((packed)) is
also a GCC extension anyway.)

> What other changes to checkpatch are needed?

I'd really suggest that we stick with the upstream checkpatch.pl and
use command line flags to tune it to coreboot (submitting patches for
new flags or cleaner detection upstream if necessary). The tool gets
updated frequently and we'd quickly fall out of sync with that if we
don't keep a clean copy that can just be uprevved regularly. Also,
this is what the Chromium tree does so maintaining a different fork of
checkpatch.pl for upstream coreboot would just make lives harder for
everyone working on Chromium (or, more likely, would just make them
commit with --no-verify all the time). Working together to improve a
common upstream would make all our lives easier.