board: amlogic: add support for AD401 board

The AD401 board is the Amlogic A1 SoC reference board

Signed-off-by: Igor Prusov <ivprusov@sberdevices.ru>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20230505125639.3605-6-ivprusov@sberdevices.ru


Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>