COMPMID-3105: Update pad layer to PadV2

Adds the ability to set the padding value in the pad layer node.

Change-Id: I2f323146cbdfdfd6cfd617ee4bcafb5ffafedbbb
Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/2727
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/arm_compute/graph/backends/FunctionHelpers.h b/arm_compute/graph/backends/FunctionHelpers.h
index 9f352ed..20c69bf 100644
--- a/arm_compute/graph/backends/FunctionHelpers.h
+++ b/arm_compute/graph/backends/FunctionHelpers.h
@@ -1048,15 +1048,16 @@
     validate_node<TargetInfo>(node, 1 /* expected inputs */, 1 /* expected outputs */);
 
     // Extract IO and info
-    typename TargetInfo::TensorType *input   = get_backing_tensor<TargetInfo>(node.input(0));
-    typename TargetInfo::TensorType *output  = get_backing_tensor<TargetInfo>(node.output(0));
-    const PaddingList               &padding = node.padding();
+    typename TargetInfo::TensorType *input     = get_backing_tensor<TargetInfo>(node.input(0));
+    typename TargetInfo::TensorType *output    = get_backing_tensor<TargetInfo>(node.output(0));
+    const PaddingList               &padding   = node.padding();
+    const PixelValue                 pad_value = node.pad_value();
     ARM_COMPUTE_ERROR_ON(input == nullptr);
     ARM_COMPUTE_ERROR_ON(output == nullptr);
 
     // Create and configure function
     auto func = support::cpp14::make_unique<PadLayerFunction>();
-    func->configure(input, output, padding);
+    func->configure(input, output, padding, pad_value);
 
     // Log info
     ARM_COMPUTE_LOG_GRAPH_INFO("Instantiated "