[M] Change in coreboot[main]: util/lint: Add lint rule to avoid duplicated includes

[Nico Huber (Code Review)]

Attention is currently required from: Arthur Heymans, Elyes Haouas, Julius Werner, Martin L Roth.

Nico Huber has posted comments on this change by Elyes Haouas. ( https://review.coreboot.org/c/coreboot/+/81907?usp=email )

Change subject: util/lint: Add lint rule to avoid duplicated includes
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Patch Set 5:

(1 comment)

File util/lint/lint-stable-031-includes:

https://review.coreboot.org/c/coreboot/+/81907/comment/850699c4_26ce68e6?usp... :
PS5, Line 56: check_duplicates '<arch/pci_ops.h>' '<device/pci_ops.h>'
I guess if we want to enforce things, we'd first have to decide on the rules?
Some things here look spurious to me (e.g. string.h), some things seem debatable.
Is it worth to discuss it all? how badly do we miss such a linter?