Figuring out whom to send a patch to is not something you can automate
because it not only depends on what you're changing but *how* you're
changing it. The classic case being that whenever you change something
related to RCU that's non-trivial, you almost certainly want to CC
Paul "RCU" McKenney. But there's no *file* or *directory* pattern that
can automatically tell you this.
Furthermore, if you're hacking on a specific part of the kernel, you
almost certainly are doing it wrong if you don't know who the relevant
maintainers are. For simple janitorial patches, you probably should
just work out the *top-level* maintainers (davem for networking, ingo
et al for x86, and so on) and send the patches to them. And when these
simple rules fail you, fall back to patch bombing Andrew.