The micro:bit board (and probably other boards using the music or display
module) locked up on soft reboot. Reason was a buffer overflow caused by
an index counter, which was not reset on soft_reboot.
That's fixed in this commit. Tested with a micro:bit board, performing a
series of soft reboots.
Signed-off-by: robert-hh <robert@hammelrath.com>
7118942a8c