Create a release_repository submodule

Change-Id: Idc49e72e9af48daf38fe675f2268d16d67193623
Signed-off-by: Isabella Gottardi <isabella.gottardi@arm.com>
diff --git a/.gitmodules b/.gitmodules
index 9933247..ca1e763 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -2,3 +2,7 @@
 	path = data
 	url = https://git.research.arm.com/ComputeLibrary/data.git
 	branch = master
+[submodule "release_repository"]
+	path = release_repository
+	url = ssh://eu-gerrit-1.euhpc.arm.com:29418/VisualCompute/Github/ComputeLibrary
+	branch = master