staging: brcm80211: removal of inactive d11 code

Code cleanup. Removed code that was never invoked because the mac core
revision supported is always higher than 22.

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>