MAINTAINERS: add missing qcow2 entry

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/MAINTAINERS b/MAINTAINERS
index f86c68a..b77131e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1872,6 +1872,7 @@
 L: qemu-block@nongnu.org
 S: Supported
 F: block/qcow2*
+F: docs/interop/qcow2.txt
 
 qcow
 M: Kevin Wolf <kwolf@redhat.com>