IVGCVSW-3546 Create a reference dynamic backend to use for testing and as
an example in the docs

 * Wrapped the reference backend into a dynamic backend
 * Moved the static registration code to a separate file, so that
   it is possible to create the reference dynamic backend that does not
   register statically into armnn
 * Added unit test

Change-Id: I1074d21b020820f9ac8c7178388be773b447555a
Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>
diff --git a/src/backends/reference/backend.mk b/src/backends/reference/backend.mk
index 6e1360a..b212995 100644
--- a/src/backends/reference/backend.mk
+++ b/src/backends/reference/backend.mk
@@ -13,6 +13,7 @@
         RefMemoryManager.cpp \
         RefTensorHandle.cpp \
         RefWorkloadFactory.cpp \
+        RefRegistryInitializer.cpp \
         workloads/Activation.cpp \
         workloads/BatchNormImpl.cpp \
         workloads/BatchToSpaceNd.cpp \