Makefile: Update the minor version to indicate 2.4 release

Updated the minor version to '4' to indicate 2.4 release

Change-Id: I0cef2f3aa58808beca2fc48acb3ad39e01619105
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/Makefile b/Makefile
index bccd45a..661f52b 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@
 
 # TFTF Version
 VERSION_MAJOR		:= 2
-VERSION_MINOR		:= 3
+VERSION_MINOR		:= 4
 
 MAKE_HELPERS_DIRECTORY := make_helpers/
 include ${MAKE_HELPERS_DIRECTORY}build_macros.mk