The private parts need USB definitions (and are thus preferably used
from USB_H_USER_IS_RIOT_INTERNAL compilation units). Functions like
usb_board_reset_in_bootloader do not depend on USB headers for their
definitions and are fair game throughout the application even for
generic RIOT USB devices.
This module implements the 2 functions called when requesting a board 'reset in application' and 'board reset in bootloader' actions.
This module will also configure the behaviour of bossa flasher and has a dependency on USBUS CDC ACM module for providing STDIO over USB