staging: brcm80211: removed 'hnd' from filenames

Cleanup. 'hnd' is a company specific acronym.

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