MAINTAINERS: Added device tree

Agreed between myself and Alex:
http://lists.nongnu.org/archive/html/qemu-devel/2012-06/msg03561.html

Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwaite@petalogix.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index e19f491..2a514fd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -511,6 +511,12 @@
 S: Maintained
 F: qemu-char.c
 
+Device Tree
+M: Peter Crosthwaite <peter.crosthwaite@petalogix.com>
+M: Alexander Graf <agraf@suse.de>
+S: Maintained
+F: device-tree.[ch]
+
 GDB stub
 M: qemu-devel@nongnu.org
 S: Odd Fixes