bonk: support decoding of files with id3 tag at the beginning

[ami_stuff]

./ffmpeg -i id3tag.bonk -y out.wav
ffmpeg version N-109341-g6b368bcb85 Copyright (c) 2000-2022 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.4.0-1ubuntu1~20.04.1)
  configuration: --enable-libopenjpeg
  libavutil      57. 43.100 / 57. 43.100
  libavcodec     59. 54.100 / 59. 54.100
  libavformat    59. 34.102 / 59. 34.102
  libavdevice    59.  8.101 / 59.  8.101
  libavfilter     8. 51.100 /  8. 51.100
  libswscale      6.  8.112 /  6.  8.112
  libswresample   4.  9.100 /  4.  9.100
[bonk @ 0x56386b883440] Format bonk detected only with low score of 1, misdetection possible!
id3tag.bonk: Invalid data found when processing input