dt-bindings: watchdog: stm32-iwdg: Document interrupt and wakeup properties

The watchdog IP can generate pre-timeout interrupt and can be used as
a wake up source. Document both properties.
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240705115052.116705-1-marex@denx.deSigned-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Documentation/devicetree/bindings/watchdog/st,stm32-iwdg.yaml

@@ -36,6 +36,12 @@ properties:
     minItems: 1
     maxItems: 2
 
+  interrupts:
+    maxItems: 1
+    description: Pre-timeout interrupt from the watchdog.
+
+  wakeup-source: true
+
 required:
   - compatible
   - reg