Extend reference model API with eager operator execution entrypoints

- Adds a script to generate operators.h and operators.cc
- Adds jinja2 templates for generating operators.h and operators.cc
- Adds unit tests for a subset of the operators generated
- Includes the TOSA specification as a submodule
- Adds supporting C++ and header files

Signed-off-by: Grant Watson <grant.watson@arm.com>
Change-Id: I5b60db4c56113110d8e75fe1152525d258233f9c
diff --git a/reference_model/CMakeLists.txt b/reference_model/CMakeLists.txt
index 04b0db5..6494225 100644
--- a/reference_model/CMakeLists.txt
+++ b/reference_model/CMakeLists.txt
@@ -66,6 +66,7 @@
     src/graph_node.cc
     src/subgraph_traverser.cc
     src/func_debug.cc
+    src/operators.cc
     src/ops/op_factory.cc
     src/ops/tensor_ops.cc
     src/ops/activation_funcs.cc