Build a fresh kernel today, ie. 3.18-rc5-wl from wireless-testing and 
got the following message while building brcmfmac:

   LD [M]  drivers/net/wireless/brcm80211/brcmfmac/brcmfmac.o
   Building modules, stage 2.
   MODPOST 2 modules
WARNING: "wiphy_new" 
[drivers/net/wireless/brcm80211/brcmfmac/brcmfmac.ko] undefined!

Did not sound encouraging to continue, but did anyway. Not surprisingly 
the insmod failed. Checking Module.symvers showed:

[arend@lb-bun-235 ~/scm/brcm80211-next]
$ grep wiphy_new Module.symvers
0xba575a46	wiphy_new_nm	net/wireless/cfg80211	EXPORT_SYMBOL

Rings a bell? We renamed the file wl_cfg80211.c that does wiphy_new() 
call to cfg80211.c. Merge issue?

Regards,
Arend