monitor: Add chardev-add backend argument completion.

Signed-off-by: Hani Benhabiles <[email protected]>
Signed-off-by: Luiz Capitulino <[email protected]>
diff --git a/hmp-commands.hx b/hmp-commands.hx
index ba88e2a..93fa534 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1623,6 +1623,7 @@
         .params     = "args",
         .help       = "add chardev",
         .mhandler.cmd = hmp_chardev_add,
+        .command_completion = chardev_add_completion,
     },
 
 STEXI