staging: brcm80211: use address space qualifier in brcmfmac

Several sparse warning were issued due to missing __user qualifier
for brcmfmac variables. This patch adds those.

Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>