[S] Change in coreboot[main]: genbuild_h: Fix and harden major/minor version parsing

[Nico Huber (Code Review)]

Attention is currently required from: Martin L Roth.

Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/81290?usp=email )

Change subject: genbuild_h: Fix and harden major/minor version parsing
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Patch Set 1:

(1 comment)

File util/genbuild_h/genbuild_h.sh:

https://review.coreboot.org/c/coreboot/+/81290/comment/19bc85b9_1c5d2be2 :
PS1, Line 39: MAJOR_VER="$(echo "${VERSION}" | sed -n 's/^0*([0-9]*).0*([0-9]*).*/\1/p')"
            : 	MINOR_VER="$(echo "${VERSION}" | sed -n 's/^0*([0-9]*).0*([0-9]*).*/\2/p')"
> > But I looked a little into sed now. If sed should support the `-E', seems in flux. […]

I've been looking some more into it. And it turns out that what is published
by the Open Group so far is the 2018 edition of Issue 7. And what they have
been cooking up for the last 15 years is Issue 8 (with the sed changes made
to the draft in 2012). IMO quite annoying when it takes decades to change
something (they got from the first version to Issue 7 within 20 years, what's
holding them back now?).

Though, I'm quite happy now that I know that people kind of agreed on `-E` for sed.
This was always annoying me that we had it for grep but not for sed. So maybe
it's time to risk using it in general (GNU, BSD and Busybox seem covered).