Sliced out Provider-ish API from ClockService

Change-Id: I438815f2dc7a3a304f7dc8fb09550b2a5f779265
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceClockManager.java b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceClockManager.java
index 4dfc88b..ff45285 100644
--- a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceClockManager.java
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceClockManager.java
@@ -12,6 +12,7 @@
 import org.apache.felix.scr.annotations.Service;
 import org.onlab.onos.cluster.MastershipTerm;
 import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.store.ClockProviderService;
 import org.onlab.onos.store.ClockService;
 import org.onlab.onos.store.Timestamp;
 import org.onlab.onos.store.impl.OnosTimestamp;
@@ -22,7 +23,7 @@
  */
 @Component(immediate = true)
 @Service
-public class DeviceClockManager implements ClockService {
+public class DeviceClockManager implements ClockService, ClockProviderService {
 
     private final Logger log = getLogger(getClass());