qmp-events: move 'MIGRATION' doc to schema

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

docs/qmp-events.txt

@@ -131,21 +131,6 @@ Flush operation:
 
 Note: this event is rate-limited.
 
-MIGRATION
----------
-
-Emitted when a migration event happens
-
-Data: None.
-
- - "status": migration status
-     See MigrationStatus in ~/qapi-schema.json for possible values
-
-Example:
-
-{"timestamp": {"seconds": 1432121972, "microseconds": 744001},
- "event": "MIGRATION", "data": {"status": "completed"}}
-
 MIGRATION_PASS
 --------------
 

qapi/event.json

@@ -410,6 +410,13 @@
 # @status: @MigrationStatus describing the current migration status.
 #
 # Since: 2.4
+#
+# Example:
+#
+# <- {"timestamp": {"seconds": 1432121972, "microseconds": 744001},
+#     "event": "MIGRATION",
+#     "data": {"status": "completed"} }
+#
 ##
 { 'event': 'MIGRATION',
   'data': {'status': 'MigrationStatus'}}