Update gitreview for v2.11, merge with branch=voltha-2.11 by default

Change-Id: I83e42f27572c6243f4973ebc4380b21e1775cab7
diff --git a/.gitreview b/.gitreview
index c04b89f..fb7779d 100644
--- a/.gitreview
+++ b/.gitreview
@@ -3,3 +3,4 @@
 port=29418
 project=ofagent-go.git
 defaultremote=origin
+defaultbranch=voltha-2.11