nanostack-libservice: add config to indicate its availability

LDong-Arm · LDong-Arm · commit ca157c9eb6e2 · 2020-09-21T14:59:32.000+01:00
diff --git a/connectivity/libraries/nanostack-libservice/mbed_lib.json b/connectivity/libraries/nanostack-libservice/mbed_lib.json
@@ -1,3 +1,6 @@
 {
-    "name": "nanostack-libservice"
+    "name": "nanostack-libservice",
+    "config": {
+        "present": 1
+    }
 }
