MAINTAINERS: add Driver Model repository information

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 68f3504..0a0de3d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -219,6 +219,7 @@
 DRIVER MODEL
 M:	Simon Glass <sjg@chromium.org>
 S:	Maintained
+T:	git git://git.denx.de/u-boot-dm.git
 F:	drivers/core/
 F:	include/dm/
 F:	test/dm/