dt-bindings: watchdog: Add support for Amlogic-T7 SoCs

Update dt-binding document for watchdog of Amlogic-T7 SoCs.

Signed-off-by: Huqiang Qin <huqiang.qin@amlogic.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230802033222.4024946-2-huqiang.qin@amlogic.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>