hw/arm: Add Olimex H405

Olimex makes a series of low-cost STM32 boards. This commit introduces
the minimum setup to support SMT32-H405. See [1] for details

[1] https://www.olimex.com/Products/ARM/ST/STM32-H405/



Signed-off-by: Felipe Balbi <balbi@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20221230145733.200496-3-balbi@kernel.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>