idualwifi7260 & iaxwifi200: Adaptations for FreeBSD/Haiku support.

Mostly a few #ifdefs for the dmamem API, if_alloc, probe, and attach hooks.
Basically the same changes in both drivers.

The firmware name map is not really needed anymore; the OpenBSD drivers
have unique firmware names and do not generally use ".ucode" extensions.
So just use the filenames as-is and drop the map.