Fix Arduino Nano 33 BLE CDC_ACM on USB port
Currently accessing the Arduino Nano over cdc_acm on the USB port is not working (instead we use the hardware UART exposed on the pins).
This needs to be debugged and fixed. It could be as simple as having the right configuration options in the default config or it might some platform or board debugging. The bootloader itself exposes a cdc_acm interface for flashing so the hardware itself can be assumed working.
Fixes need to be upstreamed to Zephyr project.