dt-bindings: watchdog: rockchip: Add rockchip,rk3588-wdt string

Add rockchip,rk3588-wdt compatible string.

Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230328210048.195124-3-shreeya.patel@collabora.com


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