MAINTAINERS: Add patchwork URL for BATMAN ADVANCED

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
diff --git a/MAINTAINERS b/MAINTAINERS
index 27393cf..4fe223a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2152,6 +2152,7 @@
 M:	Antonio Quartulli <a@unstable.cc>
 L:	b.a.t.m.a.n@lists.open-mesh.org
 W:	https://www.open-mesh.org/
+Q:	https://patchwork.open-mesh.org/project/batman/list/
 S:	Maintained
 F:	net/batman-adv/