[XS] Change in coreboot[main]: util/cbfstool: Fix linux_trampoline.c generation

[Shuo Liu (Code Review)]

Attention is currently required from: Arthur Heymans, Lean Sheng Tan, Patrick Rudolph.

Shuo Liu has posted comments on this change by Shuo Liu. ( https://review.coreboot.org/c/coreboot/+/82704?usp=email )

Change subject: util/cbfstool: Fix linux_trampoline.c generation
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Patch Set 2:

(1 comment)

Patchset:

PS1:
> Would be nice to have this build-tested

I used to manually to do the build-test here, e.g.

cd util/cbfstool/
rm linux_trampoline.c
make linux_trampoline.c

The above build steps is not linked to the overall coreboot board target build flow. I added it into the commit message.