feat(plat/st/stm32mp1): add USB DFU support for STM32MP1

Add the USB descriptor, the struct used for USB enumeration with
the function usb_dfu_plat_init().

The USB support is based on the usb lib and on the stm32mp1 usb driver.

The content of enumeration (the string descriptor) is identical to
ROM code to avoid the USB reset en re-enumeration needs.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Change-Id: I18b40649e8df83813a5a340b0eee44c9a3470e43
2 files changed