Fixup release notes for v2 -> v2.1 replication impls

A few drivers got changes in for v2 replication in with release notes
and then didn’t update them once v2.1 came into the picture.

Change-Id: Ia3ba872aa8f7868f572b5cf45714639c2c079e7f

releasenotes/notes/3par-v2-replication-unmanaged-13f3d6a52198a7a6.yaml

@@ -1,3 +0,0 @@
----
-features:
-  - Added unmanaged v2 replication support to the HPE 3PAR driver.

releasenotes/notes/lefthand-v2-replication-managed-ca38e9f2e8a1be6b.yaml

@@ -1,3 +0,0 @@
----
-features:
-  - Added managed v2 replication support to the HPE LeftHand driver.

releasenotes/notes/lefthand-v2-replication-unmanaged-315c2888423f0f3b.yaml

@@ -1,3 +0,0 @@
----
-features:
-  - Added unmanaged v2 replication support to the HPE LeftHand driver.

releasenotes/notes/pure-v2-replication-0246223caaa8a9b5.yaml

@@ -1,3 +0,0 @@
----
-features:
-  - Added v2 replication support to the Pure Volume driver.

releasenotes/notes/pure-v2.1-replication-0246223caaa8a9b5.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - Added Cheesecake (v2.1) replication support to the Pure Storage Volume
+    drivers.