dt-bindings: watchdog: fsl-imx7ulp-wdt: Fix assigned-clock-parents

The schema has a typo with 'assigned-clocks-parents'. As it is not
required to list assigned clocks in bindings, just drop the assigned-clocks
property definitions to fix this.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220120172333.1628990-1-robh@kernel.org

Documentation/devicetree/bindings/watchdog/fsl-imx7ulp-wdt.yaml

@@ -29,12 +29,6 @@ properties:
   clocks:
     maxItems: 1
 
-  assigned-clocks:
-    maxItems: 1
-
-  assigned-clocks-parents:
-    maxItems: 1
-
   timeout-sec: true
 
 required:
@@ -56,7 +50,7 @@ examples:
         interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>;
         clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
         assigned-clocks = <&pcc2 IMX7ULP_CLK_WDG1>;
-        assigned-clocks-parents = <&scg1 IMX7ULP_CLK_FIRC_BUS_CLK>;
+        assigned-clock-parents = <&scg1 IMX7ULP_CLK_FIRC_BUS_CLK>;
         timeout-sec = <40>;
     };