MAINTAINERS: change broken url for prism54

Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 44620ae..8e85429 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4549,7 +4549,7 @@
 PRISM54 WIRELESS DRIVER
 M:	"Luis R. Rodriguez" <mcgrof@gmail.com>
 L:	linux-wireless@vger.kernel.org
-W:	http://prism54.org
+W:	http://wireless.kernel.org/en/users/Drivers/p54
 S:	Obsolete
 F:	drivers/net/wireless/prism54/