block: Factor out hmp_change_medium(), and move to block/monitor/

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230124121946.1139465-13-armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
index 58ed1be..6fafa7f 100644
--- a/include/monitor/hmp.h
+++ b/include/monitor/hmp.h
@@ -78,6 +78,9 @@
                     const char *arg, const char *read_only, bool force,
                     Error **errp);
 #endif
+void hmp_change_medium(Monitor *mon, const char *device, const char *target,
+                       const char *arg, const char *read_only, bool force,
+                       Error **errp);
 void hmp_migrate(Monitor *mon, const QDict *qdict);
 void hmp_device_add(Monitor *mon, const QDict *qdict);
 void hmp_device_del(Monitor *mon, const QDict *qdict);