dt-bindings: watchdog: meson-gxbb-wdt: Include generic watchdog bindings

Include generic watchdog DT schema bindings in Amlogic GXBB Watchdog
bindings.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/watchdog/amlogic,meson-gxbb-wdt.yaml

@@ -10,6 +10,9 @@ title: Meson GXBB SoCs Watchdog timer
 maintainers:
   - Neil Armstrong <narmstrong@baylibre.com>
 
+allOf:
+  - $ref: watchdog.yaml#
+
 properties:
   compatible:
     enum: