dt-bindings: mfd: da9062: Correct file name for watchdog

Replace the watchdog file name with the name currently in use.
Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221130101426.5318-1-cniedermaier@dh-electronics.com

Documentation/devicetree/bindings/mfd/da9062.txt

@@ -86,7 +86,7 @@ Sub-nodes:
 
 - onkey : See ../input/da9062-onkey.txt
 
-- watchdog: See ../watchdog/da9062-watchdog.txt
+- watchdog: See ../watchdog/da9062-wdt.txt
 
 - thermal : See ../thermal/da9062-thermal.txt