Add code coverage tool

Change-Id: I9a90ba54af84b03165f395d97c9067acb10db0ec
Signed-off-by: Raef Coles <raef.coles@arm.com>
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..95c151a
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "code_coverage/qa-tools"]
+	path = code_coverage/qa-tools
+	url = https://git.gitlab.arm.com/tooling/qa-tools.git