Merge pull request #12565 from dkurt:dnn_non_intel_gpu

* Remove isIntel check from deep learning layers

* Remove fp16->fp32 fallbacks where it's not necessary

* Fix Kernel::run to prevent localsize > globalsize

modules/dnn/src/layers/split_layer.cpp

@@ -83,12 +83,6 @@ public:
         CV_TRACE_FUNCTION();
         CV_TRACE_ARG_VALUE(name, "name", name.c_str());
 
-        if (inputs_arr.depth() == CV_16S)
-        {
-            forward_fallback(inputs_arr, outputs_arr, internals_arr);
-            return;
-        }
-
         std::vector<Mat> inputs, outputs;
         inputs_arr.getMatVector(inputs);
         outputs_arr.getMatVector(outputs);