brcmfmac: fix build regression

This fixes a build regression for x86_64 target that showed up
in 3.7-rc1 due to:

commit 1a873342
Author: Hante Meuleman <meuleman@broadcom.com>
Date:   Thu Sep 27 14:17:54 2012 +0200

    brcmfmac: add hostap supoort.

Reported-by: Yuanhan Liu <yuanhan.liu@intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>