c-user: Document rtems_object_get_local_node()

Close #3841.

c-user/object_services.rst

@@ -49,6 +49,8 @@ them.  The object related services provided by RTEMS are:
 
 - rtems_object_get_class_information_ - obtain class information
 
+- rtems_object_get_local_node_ - obtain local node
+
 Background
 ==========
 
@@ -785,3 +787,29 @@ DESCRIPTION:
 
 NOTES:
     This directive is strictly local and does not impact task scheduling.
+
+.. raw:: latex
+
+   \clearpage
+
+.. index:: obtain local node
+.. index:: rtems_object_get_local_node
+
+.. _rtems_object_get_local_node:
+
+OBJECT_GET_LOCAL_NODE - Obtain Local Node
+-----------------------------------------
+
+CALLING SEQUENCE:
+    .. code-block:: c
+
+        uint16_t rtems_object_get_local_node( void );
+
+DIRECTIVE STATUS CODES:
+    NONE
+
+DESCRIPTION:
+    This service returns the local MPCI node.
+
+NOTES:
+    This directive is strictly local and does not impact task scheduling.