cmake HAVE_DNN_NGRAPH examples

SsageParuders/Android_Native_Surface my_android_opencv/cmake/OpenCVDetectInferenceEngine.cmake :75 

list(APPEND defs "HAVE_NGRAPH" "HAVE_DNN_NGRAPH")

joachimBurket/esp32-opencv modules/dnn/CMakeLists.txt :119 

add_definitions(-DHAVE_DNN_NGRAPH)