ObjectMapper: Add default paths

The ObjectMapper service is expected to be at a specific location per
the description.  Document this with code constants as well.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I6623d56ae5cfd01a55ffe628bd68c5fcfd3da1dc
diff --git a/yaml/xyz/openbmc_project/ObjectMapper.interface.yaml b/yaml/xyz/openbmc_project/ObjectMapper.interface.yaml
index c7b8c78..0fd1be5 100644
--- a/yaml/xyz/openbmc_project/ObjectMapper.interface.yaml
+++ b/yaml/xyz/openbmc_project/ObjectMapper.interface.yaml
@@ -3,6 +3,7 @@
 
     Any OpenBMC implementation must provide exactly one implementation of
     xyz.openbmc_project.ObjectMapper on /xyz/openbmc_project/ObjectMapper.
+
 methods:
     - name: GetObject
       description: >
@@ -152,3 +153,9 @@
                 An array of paths.
       errors:
           - xyz.openbmc_project.Common.Error.ResourceNotFound
+
+service_names:
+    - default: xyz.openbmc_project.ObjectMapper
+
+paths:
+    - instance: /xyz/openbmc_project/object_mapper