MAINTAINERS: Cover qapi/stats.json

Commit aa09b3d (stats: Move QMP commands from monitor/ to stats/)
created section Stats, but neglected to add qapi/stats.json to it.
Fix that.

Signed-off-by: Markus Armbruster <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Signed-off-by: Michael Tokarev <[email protected]>

Author: Markus Armbruster

MAINTAINERS

@@ -3321,6 +3321,7 @@ Stats
 S: Orphan
 F: include/sysemu/stats.h
 F: stats/
+F: qapi/stats.json
 
 Streams
 M: Edgar E. Iglesias <[email protected]>