sdbus++: Use native types for obj-path and signature

Change-Id: I6075a6a52553d0dc7dca6abc3442282f91fb5d44
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/tools/sdbusplus/property.py b/tools/sdbusplus/property.py
index ba98931..7ed53ed 100644
--- a/tools/sdbusplus/property.py
+++ b/tools/sdbusplus/property.py
@@ -113,8 +113,10 @@
             'uint64': {'cppName': 'uint64_t', 'params': 0},
             'double': {'cppName': 'double', 'params': 0},
             'string': {'cppName': 'std::string', 'params': 0},
-            'path': {'cppName': 'std::string', 'params': 0},
-            'signature': {'cppName': 'std::string', 'params': 0},
+            'path': {'cppName': 'sdbusplus::message::object_path',
+                     'params': 0},
+            'signature': {'cppName': 'sdbusplus::message::signature',
+                          'params': 0},
             'array': {'cppName': 'std::vector', 'params': 1},
             'struct': {'cppName': 'std::tuple', 'params': -1},
             'variant': {'cppName': 'sdbusplus::message::variant',