* Can be combined with CUDA (and HIP/ROCm also shipping with OpenCL).
* Improved handing CUDA (determining CUDA_PATH from nvcc's directory).
* Avoid CUDA settings for ARCH-files without CUDA (unrelated bug).
* Note: OpenCL support is currently limited to DBCSR component
* Ensure LIBXSMM is enabled when enabling OpenCL backend.
* Handle OpenCL during ARCH-file generation.
* Parse IF_OPENCL.
* Cleanup.