dt-bindings: watchdog: atmel: Add missing 'interrupts' property

With 'unevaluatedProperties' support implemented, the atmel,sama5d4-wdt
example has the following warning:

/home/rob/proj/git/linux-dt/.build-arm64/Documentation/devicetree/bindings/watchdog/atmel,sama5d4-wdt.example.dt.yaml: watchdog@fc068640: Unevaluated properties are not allowed ('interrupts' was unexpected)

Document the missing 'interrupts' property.

Cc: Wim Van Sebroeck <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Nicolas Ferre <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: Ludovic Desroches <[email protected]>
Cc: Eugen Hristev <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Rob Herring <[email protected]>
Acked-by: Guenter Roeck <[email protected]>
Reviewed-by: Thierry Reding <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Guenter Roeck <[email protected]>
Signed-off-by: Wim Van Sebroeck <[email protected]>

Author: robherring

Documentation/devicetree/bindings/watchdog/atmel,sama5d4-wdt.yaml

@@ -22,6 +22,9 @@ properties:
   reg:
     maxItems: 1
 
+  interrupts:
+    maxItems: 1
+
   atmel,watchdog-type:
     $ref: /schemas/types.yaml#/definitions/string
     description: should be hardware or software.