staging: brcm80211: wlc_aggregatable function prototype moved

The function wlc_aggregatable is used by wl_mac80211.c. The prototype
of the function was placed in include file wlc_scb.h but the interface
for wl_mac80211.c to other driver functions is to be placed in wlc_pub.h.

Cc: devel@linuxdriverproject.org
Cc: linux-wireless@vger.kernel.org
Reviewed-by: Roland Vossen <rvossen@broadcoom.com>
Reviewed-by: Henry Ptasinski <henryp@broadcom.com>
Reviewed-by: Brett Rudley <brudley@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>