bug#63072: 28.2; CC Mode: Fix "bsd" style and add "freebsd" and "openbsd" ones

[Eli Zaretskii]

> From: Olivier Certner <ocert.dev@free.fr>
> Date: Tue, 25 Apr 2023 19:49:09 +0200
> 
> I noticed that the current "bsd" CC mode style is not compliant with what all 
> BSDs have been doing since their inception. This is the first patch.

ENOPATCH, but in any case, I don't think we can change a style that
was in use for such a long time.  So I suggest instead to create a new
style, say bsd2 or somesuch.