o move ath hal os glue code from the hal to the driver: this code was

part of the hal distribution early on when the hal was built for
each os but it's been portable for a long time so move the os-specific
code out (and off the vendor branch)

o correct the copyright on ah_osdep.?; it was mistakenly given a

restricted license and not a dual-bsd/gpl license

o remove the module api definition as it was never used
o fixup include paths for move of ah_osdep.h

MFC after: 2 weeks