genassym: Remove stale *if.h depends

[imp]

Summary

Since we no longer need to include intr.h, which depends on sys/bus.h,
in genassym, we no longer need to include it in the Makefile depends.

Sponsored by: Netflix

[ehem_freebsd_m5p.com]

This seems reasonable, though I'm concerned with the present approach.

Isn't the underlying problem <sys/bus.h> has turned into a cesspool? In particular types and constants presently in <sys/bus.h> are being #include'd all over the place. The above is the result of #include "bus_if.h" and #include "device_if.h" being added in.

Might it be better to move lines 213-296 of <sys/bus.h> (FILTER_STRAY to enum intr_polarity) to sys/sys/_types_interrupt.h and then have sys/interrupt.h include that header?

If that is done, then <sys/bus.h> will still be >1000 lines. Likely <sys/bus.h> needs to be further broken into 3-5+ files beyond this.

[imp]

Longer term, maybe. But for now this series gets the job done in the most efficient way possible.
We don't need all of this extra junk, so why optimize for all this extra junk is kinda how I look at it.

[ehem_freebsd_m5p.com]

Yet the solution to the underlying issue is also quite simple (already have a commit on GH, I can upload to Phabricator if desired), so perhaps that should be considered? If nothing else that gives an additional option which may turn out rather superior for the long term. The underlying issue has likely been causing all sorts of (perhaps minor) trouble for some already.