staging: brcm80211: shuffled sections in main.c

Moved bmac functions above 'common' functions invoking them. This facilitates
merging these functions in a later commit. Also declared locally used
functions static.

Signed-off-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>