staging: brcm80211: removed unused code because of mac rev cleanup

Code cleanup. Removed more defines, data structures and functions that were
unused because this driver supports mac core rev 22 and up. Got rid of redundant
brackets in wlc_bmac_txstatus() by moving locally defined variables above {}
scope.

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