Add opencl for Hwaccel

[FalsePhilosopher]

I hashed out the workings of getting HWaccel in ffmpeg working with yt-dlp, the args for a mobile device looks like --ppa "ModifyChapters+ffmpeg_i:-hwaccel opencl -hwaccel_output_format opencl" --ppa "ModifyChapters+ffmpeg_o:-c:v hevc_mediacodec" Most phones since 2015 have TPU's(NPU's) in them that you can run opencl on and use the TPU/GPU in conjunction to speed up encoding when using the --sponsor-block arg. It dramatically cuts encode times off, I encoded a 30 min 720p video with the sponsor block arg in 3 or so minutes at 2% battery usage. So you will need to add the opencl libraries. Since I am requesting features can we use whatever code or clean room what newpipe is using to hit the youtube api for searching and displaying videos? Calling a youtube webapp shell in a window or something so we don't have to switch back and forth between a web browser to seal for getting download links?