exploder5: fix assignments for daughter board (audio + rs232)
exploder5: cut clock crossing for audio chip
exploder5: update top file

- connect audio chip
- make audio pins open drain
- wire rs232 to WR, and remove extra not-layouted pins
- use base board 1wire
- remove button LEDs not in final daughter board
nau8811: ignore generated files
exploder5: working 1wire