Incrementing the minor version to reflect upcoming v2.3 release

Change-Id: I27f7d92988fc16f68041c2ddaa8dd3a60362ddd1
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

Makefile

@@ -8,7 +8,7 @@
 # Trusted Firmware Version
 #
 VERSION_MAJOR			:= 2
-VERSION_MINOR			:= 2
+VERSION_MINOR			:= 3
 
 # Default goal is build all images
 .DEFAULT_GOAL			:= all