Merge pull request #10992 from dkurt:dnn_opencl_tests

diff --cc modules/dnn/src/layers/convolution_layer.cpp
Simple merge

diff --cc modules/dnn/src/layers/fully_connected_layer.cpp
Simple merge

diff --cc modules/dnn/src/layers/lrn_layer.cpp
Simple merge

diff --cc modules/dnn/src/layers/pooling_layer.cpp
Simple merge

diff --cc modules/dnn/src/layers/softmax_layer.cpp
Simple merge