[airborne] fix code style on (nearly) all files

```
find sw/airborne/ -regextype posix-extended -regex 'sw/airborne/.*(chibios-libopencm3|lpcusb|efsl|lpc21/include|lpc21/test/bootloader)' -prune -o -name '*.[ch]' -exec ./fix_code_style.sh {} +
```

closes #617