object: add more commands to preconfig mode

Creating and destroying QOM objects does not require a fully constructed
machine.  Allow running object-add and object-del before machine
initialization has concluded.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

qapi/qom.json

@@ -857,7 +857,8 @@
 # <- { "return": {} }
 #
 ##
-{ 'command': 'object-add', 'data': 'ObjectOptions', 'boxed': true }
+{ 'command': 'object-add', 'data': 'ObjectOptions', 'boxed': true,
+  'allow-preconfig': true }
 
 ##
 # @object-del:
@@ -877,4 +878,5 @@
 # <- { "return": {} }
 #
 ##
-{ 'command': 'object-del', 'data': {'id': 'str'} }
+{ 'command': 'object-del', 'data': {'id': 'str'},
+  'allow-preconfig': true }