feat(plat/st/stm32mp1): add STM32MP_USB_PROGRAMMER target

Add a support of USB as serial boot devices for STM32MP15x platform:
the FIP file is provide by STM32CubeProgrammer with the DFU protocol,
loaded in DDR at DWL_BUFFER_BASE address and then the io memmap is used.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Change-Id: I272c17c458ff1e9d0780f8fa22330c8a35533d19
5 files changed