arm64: dts: meson: a1: add ao secure node

arm64: dts: meson: a1: add ao secure node

Add node for board info registers, which allows getting SoC family and
board revision.

For example, with MESON_GX_SOCINFO config enabled we can get the
following information for board with Meson A1 SoC:
    soc soc0: Amlogic Meson A1 (A113L) Revision 2c:a (1:a) Detected

Signed-off-by: Alexey Romanov <avromanov@sberdevices.ru>
Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20230823213630.12936-14-ddrokosov@sberdevices.ru
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>