brcmsmac: add a conditions for core rev 17 again

This reverts some changes made in this commit:
commit 72345923
Author: Roland Vossen <rvossen@broadcom.com>
Date:   Mon Feb 14 12:16:45 2011 +0100

    staging: brcm80211: removal of inactive d11 code

The bcm4716 has a rev 17 wireless core and this condition is needed.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>