Enable libmfx

Author: jasworks

build-ffmpeg

@@ -930,6 +930,7 @@ download "https://github.com/FFmpeg/FFmpeg/archive/refs/heads/release/$FFMPEG_VE
  --enable-small \
  --enable-version3 \
  --enable-network --enable-protocol=tcp --enable-demuxer=rtsp \
+ --enable-libmfx \
  --disable-ffnvcodec \
  --extra-cflags="${CFLAGS}" \
  --extra-ldexeflags="${LDEXEFLAGS}" \