Just thought I'd post my solution in case anyone else comes across this problem.
This fix solves the error, I can't guarantee it'll compile a complete driver just yet as my kernel has other problems.
Add wl_iw.o to DHDOFILES in bcmdhd/Makefile
Add
to bcmdhd/wl_iw.c above
Code:
#if defined(USE_IW)
m0tter