Port DepthConvert to new Api

- Renames DepthConvert to Cast
- Ports both NEDepthConverLayer and CLDepthConvert variants
- Removes legacy shift capability from DepthConvert, allowing only
shifts of 0

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: I806a0f8eb23d23502b632c529fda7edde19c8176
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5565
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/core/gpu/cl/ClKernelLibrary.cpp b/src/core/gpu/cl/ClKernelLibrary.cpp
index 286ed4c..b0458d7 100644
--- a/src/core/gpu/cl/ClKernelLibrary.cpp
+++ b/src/core/gpu/cl/ClKernelLibrary.cpp
@@ -216,8 +216,8 @@
     { "concatenate_width_x2", "concatenate.cl" },
     { "concatenate_width_x4", "concatenate.cl" },
     { "col2im", "col2im.cl" },
-    { "convert_depth_down", "depth_convert.cl" },
-    { "convert_depth_up", "depth_convert.cl" },
+    { "cast_down", "cast.cl" },
+    { "cast_up", "cast.cl" },
     { "convert_fc_weights", "convert_fc_weights.cl" },
     { "copy_tensor", "copy_tensor.cl" },
     { "crop_tensor", "crop_tensor.cl" },
@@ -565,8 +565,8 @@
 #include "./cl_kernels/deconvolution_layer.clembed"
     },
     {
-        "depth_convert.cl",
-#include "./cl_kernels/depth_convert.clembed"
+        "cast.cl",
+#include "./cl_kernels/cast.clembed"
     },
     {
         "depth_to_space.cl",