Allow rebooting devices with non usb_stdio PID

[zeha]

Looking at the picotool source, the feature to reboot a running application into BOOTSEL mode is hidden behind a check for the stdio_usb vid/pid.
It would be very useful to allow passing a custom vid/pid, for devices that want to reuse the stdio_usb reset_interface code, but otherwise want a custom vid/pid.

Such a setup is currently under consideration for the MNT Pocket Reform open hardware: https://mntre.com/reform.html