sdbus++: add type 'object_path' alias

The underlying dbus and sdbusplus type is 'object_path', but the
current sdbus++ type is 'path'.  Add an alias which is more obvious.

There are currently some users of 'path' is phosphor-dbus-interfaces,
so we cannot immediately remove 'path'.  Once this is merged we can
migrate them to 'object_path'.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Iee65fefe890b7bef351a39fa9fec403d3a086a78
diff --git a/test/server/Test.interface.yaml b/test/server/Test.interface.yaml
index 2b6c9f5..ac36b84 100644
--- a/test/server/Test.interface.yaml
+++ b/test/server/Test.interface.yaml
@@ -15,4 +15,4 @@
     - name: Countable
       type: size
     - name: ObjectPath
-      type: path
+      type: object_path
diff --git a/tools/sdbusplus/property.py b/tools/sdbusplus/property.py
index 777025c..6eb952e 100644
--- a/tools/sdbusplus/property.py
+++ b/tools/sdbusplus/property.py
@@ -161,6 +161,8 @@
             'string': {'cppName': 'std::string', 'params': 0},
             'path': {'cppName': 'sdbusplus::message::object_path',
                      'params': 0},
+            'object_path': {'cppName': 'sdbusplus::message::object_path',
+                            'params': 0},
             'signature': {'cppName': 'sdbusplus::message::signature',
                           'params': 0},
             'array': {'cppName': 'std::vector', 'params': 1},