dt-bindings: watchdog: add exynosautov9 compatible

Adds "samsung,exynosautov9-wdt" to samsung-wdt compatible. This has two
cpu watchdogs like exynos850.

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220520121750.71473-2-chanho61.park@samsung.com


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