ar9170usb: mark the old driver as obsolete

AR9170USB will be replaced by carl9170 in the foreseeable
future [2.6.40].

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 2b35b6c8..95482e9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1199,7 +1199,7 @@
 M:	Christian Lamparter <chunkeey@web.de>
 L:	linux-wireless@vger.kernel.org
 W:	http://wireless.kernel.org/en/users/Drivers/ar9170
-S:	Maintained
+S:	Obsolete
 F:	drivers/net/wireless/ath/ar9170/
 
 CARL9170 LINUX COMMUNITY WIRELESS DRIVER