Change the second type parameter of BatchOperationEntry

- Remove the bounded type parameter for BatchOperationTarget
- FlowRule and Intent don't inherit from BatchOperationTarget
- Remove BatchOperationTarget because nothing depends on it

Change-Id: I3b414d25409e9bbe5de37ffef10b08bc1799be74
diff --git a/core/api/src/main/java/org/onosproject/net/flow/BatchOperationEntry.java b/core/api/src/main/java/org/onosproject/net/flow/BatchOperationEntry.java
index b5ad2ef..fc24775 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/BatchOperationEntry.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/BatchOperationEntry.java
@@ -27,7 +27,7 @@
  * This is the interface to classes which are maintained by BatchOperation as
  * its entries.
  */
-public class BatchOperationEntry<T extends Enum<?>, U extends BatchOperationTarget> {
+public class BatchOperationEntry<T extends Enum<?>, U> {
 
     private final T operator;
     private final U target;