COMPMID-417: Fix DepthConcatenate validation fixture

Change-Id: I4d15b4f31ed571e275a47e254c9df9ba9c95eb82
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/87316
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
diff --git a/tests/validation/fixtures/DepthConcatenateLayerFixture.h b/tests/validation/fixtures/DepthConcatenateLayerFixture.h
index 2a2e96e..633dba2 100644
--- a/tests/validation/fixtures/DepthConcatenateLayerFixture.h
+++ b/tests/validation/fixtures/DepthConcatenateLayerFixture.h
@@ -38,16 +38,11 @@
 
 namespace arm_compute
 {
-class ITensor;
-class Tensor;
-class ICLTensor;
-class CLTensor;
-
 namespace test
 {
 namespace validation
 {
-template <typename TensorType, typename AccessorType, typename FunctionType, typename T>
+template <typename TensorType, typename ITensorType, typename AccessorType, typename FunctionType, typename T>
 class DepthConcatenateValidationFixture : public framework::Fixture
 {
 public:
@@ -99,8 +94,6 @@
 
     TensorType compute_target(std::vector<TensorShape> shapes, DataType data_type)
     {
-        using ITensorType = typename std::conditional<std::is_same<TensorType, Tensor>::value, ITensor, ICLTensor>::type;
-
         std::vector<TensorType>    srcs;
         std::vector<ITensorType *> src_ptrs;