it adds OPENCV_TINY_GPU_MODULE definition, that will allow
to build tiny version of gpu module (with limited image format support)

Without the fix, OpenCV will compile and silently copy the compiled libs/executables to a location not prefixed with arch/vc14, and OpenCV won't be picked up by find_package and OpenCVConfig.cmake.

It hasn't been used since f82c04f4. Also, the line adding the script had
an unneeded pathto call, so the script was being loaded from the wrong path
anyway.