Rename ported functions

Rename CpuPooling to CpuPool2d
Rename CpuPoolingKernel to CpuPool2dKernel
Rename CpuPoolingAssemblyWrapperKernel to CpuPool2dAssemblyWrapperKernel
Move CpuPool2dAssemblyWrapperKernel in internal subfolder
Rename CpuDepthwiseConvolutionNativeKernel to CpuDepthwiseConv2dNativeKernel
Rename CpuDepthwiseConvolutionAssemblyDispatch to CpuDepthwiseConv2dAssemblyDispatch
Rename CpuDepthwiseConvolution to CpuDepthwiseConv2d
Rename CpuDirectConvolutionKernel to CpuDirectConv2dKernel
Rename CpuDirectConvolutionOutputStageKernel to CpuDirectConv2dOutputStageKernel
Rename CpuDirectConvolution to CpuDirectConv2d
Rename ClPoolingKernel to ClPool2dKernel
Rename ClPooling to ClPool2d
Rename ClDirectConvolutionKernel to ClDirectConv2dKernel

Resolves: COMPMID-4405

Change-Id: I8e48f015e4e492a76a7512f5679cb3eb0cd028f6
Signed-off-by: Manuel Bottini <manuel.bottini@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5708
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/runtime/NEON/functions/NEDirectConvolutionLayer.cpp b/src/runtime/NEON/functions/NEDirectConvolutionLayer.cpp
index 7383438..58530e4 100644
--- a/src/runtime/NEON/functions/NEDirectConvolutionLayer.cpp
+++ b/src/runtime/NEON/functions/NEDirectConvolutionLayer.cpp
@@ -27,17 +27,17 @@
 #include "arm_compute/core/Utils.h"
 #include "arm_compute/core/Validate.h"
 #include "arm_compute/runtime/NEON/NEScheduler.h"
-#include "src/runtime/cpu/operators/CpuDirectConvolution.h"
+#include "src/runtime/cpu/operators/CpuDirectConv2d.h"
 
 namespace arm_compute
 {
 struct NEDirectConvolutionLayer::Impl
 {
-    ITensor                                   *src{ nullptr };
-    const ITensor                             *weights{ nullptr };
-    const ITensor                             *bias{ nullptr };
-    ITensor                                   *dst{ nullptr };
-    std::unique_ptr<cpu::CpuDirectConvolution> op{ nullptr };
+    ITensor                              *src{ nullptr };
+    const ITensor                        *weights{ nullptr };
+    const ITensor                        *bias{ nullptr };
+    ITensor                              *dst{ nullptr };
+    std::unique_ptr<cpu::CpuDirectConv2d> op{ nullptr };
 };
 
 NEDirectConvolutionLayer::NEDirectConvolutionLayer(std::shared_ptr<IMemoryManager> memory_manager)
@@ -52,14 +52,14 @@
     _impl->weights = weights;
     _impl->bias    = bias;
     _impl->dst     = output;
-    _impl->op      = std::make_unique<cpu::CpuDirectConvolution>(_memory_manager);
+    _impl->op      = std::make_unique<cpu::CpuDirectConv2d>(_memory_manager);
     _impl->op->configure(input->info(), weights->info(), (bias != nullptr ? bias->info() : nullptr), output->info(), conv_info, act_info);
 }
 
 Status NEDirectConvolutionLayer::validate(const ITensorInfo *input, const ITensorInfo *weights, const ITensorInfo *bias, const ITensorInfo *output, const PadStrideInfo &conv_info,
                                           const ActivationLayerInfo &act_info)
 {
-    return cpu::CpuDirectConvolution::validate(input, weights, bias, output, conv_info, act_info);
+    return cpu::CpuDirectConv2d::validate(input, weights, bias, output, conv_info, act_info);
 }
 
 void NEDirectConvolutionLayer::run()