VOL-2378 Release voltha-openolt-adapter 2.2.5

Change-Id: I5a746d7492de57ef302c119eec6d140ab7f329d4
diff --git a/VERSION b/VERSION
index 7c8d436..21bb5e1 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.2.5-dev
+2.2.5