staging: brcm80211: rename structure definitions in dhd.h

Structure definitions in dhd.h have been prefixed with brcmf_ for
consistent naming in fullmac driver and typedef of these structures
has been removed.

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