staging: brcm80211: made name lookup arrays more const

The checkpatch script gave a hint that some character string arrays
probably should have an additional const keyword. This patch changes
the static const char * arrays to static const char * const arrays as
suggested getting rid of two checkpatch warnings.

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