ONOS-2926 Remove IP instead of host when the IP mapping is released

Change-Id: Ifea3366ce8a18ea068e615636b3069e769221c0e
diff --git a/core/api/src/main/java/org/onosproject/net/host/HostStore.java b/core/api/src/main/java/org/onosproject/net/host/HostStore.java
index 5894fe9..918ced4 100644
--- a/core/api/src/main/java/org/onosproject/net/host/HostStore.java
+++ b/core/api/src/main/java/org/onosproject/net/host/HostStore.java
@@ -55,6 +55,15 @@
     HostEvent removeHost(HostId hostId);
 
     /**
+     * Removes the specified ip from the host entry.
+     *
+     * @param hostId host identification
+     * @param ipAddress ipAddress to be removed
+     * @return remove event or null if host was not found
+     */
+    HostEvent removeIp(HostId hostId, IpAddress ipAddress);
+
+    /**
      * Returns the number of hosts in the store.
      *
      * @return host count