COMPMID-3393: Minor tweaks on memory injection interface

* Avoid the need to overload workspace() everytime
* Remove the Layer suffix from the operators
* Clean interface by removing default arguments when unsupported

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I7710ecd485cae13e9c2d45216debbd8103bc5a0f
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/3610
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michalis Spyrou <michalis.spyrou@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/arm_compute/runtime/CL/functions/CLConcatenateLayer.h b/arm_compute/runtime/CL/functions/CLConcatenateLayer.h
index 4e8a95b..99a2053 100644
--- a/arm_compute/runtime/CL/functions/CLConcatenateLayer.h
+++ b/arm_compute/runtime/CL/functions/CLConcatenateLayer.h
@@ -113,11 +113,11 @@
  * -# @ref CLDepthConcatenateLayerKernel (if underlying concatenation axis is 2).
  * -# @ref CLBatchConcatenateLayerKernel (if underlying concatenation axis is 3).
  */
-class CLConcatenateLayer : public ICLOperator
+class CLConcatenation : public ICLOperator
 {
 public:
     /** Default constructor */
-    CLConcatenateLayer();
+    CLConcatenation();
     /** Initialise the kernel's inputs vector and output.
      *
      * @note Input and output tensor dimensions preconditions defer depending on the concatenation axis.
@@ -144,7 +144,6 @@
     static Status validate(const std::vector<const ITensorInfo *> &inputs_vector, const ITensorInfo *output, size_t axis);
 
     // Inherited methods overridden:
-    MemoryRequirements workspace() const override;
     void run(InputTensorMap inputs, OutputTensorMap outputs, OperatorTensorMap workspace) override;
 
 private: