MAINTAINERS: add b43 mailing list

Signed-off-by: NRafał Miłecki <zajec5@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

MAINTAINERS

@@ -1411,6 +1411,7 @@ F:	net/ax25/
 B43 WIRELESS DRIVER
 M:	Stefano Brivio <stefano.brivio@polimi.it>
 L:	linux-wireless@vger.kernel.org
+L:	b43-dev@lists.infradead.org (moderated for non-subscribers)
 W:	http://linuxwireless.org/en/users/Drivers/b43
 S:	Maintained
 F:	drivers/net/wireless/b43/