staging: brcm80211: remove external definitions from phy_lcn.c

The source file phy_lcn.c had several external definitions flagged
by checkpatch.pl script. The patch fixes those.

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