Architecture support for STMicroelectronics STMU585xx MCUs. This is
based on corresponding code for STM32L5, but has been considerably
adjusted. Tested with a B-U585I-IOT02A board and a simple NSH
configuration, but only running NuttX in the non-secure world with
TrustedFirmware-M.
Signed-off-by: Michael Jung <mijung@gmx.net>
