tty: serial: meson: Add a earlycon for the T7 SoC

The new Amlogic T7 SoC does not have a always-on uart,
so add OF_EARLYCON_DECLARE for it.

Signed-off-by: Lucas Tanure <tanure@linux.com>
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20230814080128.143613-2-tanure@linux.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>