usb_disconnect() is board/platform specific for chips that don't have built-in handling for this. Allow the application to provide its own version of usb_disconnect() to handle this. See https://github.com/libopencm3/libopencm3/pull/924
usb_disconnect() is board/platform specific for chips that don't have built-in handling for this. Allow the application to provide its own version of usb_disconnect() to handle this. See https://github.com/libopencm3/libopencm3/pull/924