A recent version of arm-none-eabi-gcc (8.2.0) will warn about unused packed
attributes in USB_WritePacket and USB_ReadPacket. This patch suppresses
such warnings for this file only.
Mboot is a custom bootloader for STM32 MCUs. It can provide a USB DFU
interface on either the FS or HS peripherals, as well as a custom I2C
bootloader interface.