staging: brcm80211: remove d11regs_t parameter from wlc_tbtt function

The function wlc_tbtt() has variable regs as parameter, but it is
not used. Parameter has been removed from the function.

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>