ARM: dts: imx35: Remove invalid wdog property

The 'clock-names' property is not a valid property for wdog.

Remove it to fix the following DT check warning:

watchdog@53fdc000: Unevaluated properties are not allowed ('clock-names' was unexpected)
From schema: Documentation/devicetree/bindings/watchdog/fsl-imx-wdt.yaml
Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx35.dtsi

@@ -298,7 +298,6 @@ wdog: watchdog@53fdc000 {
 				compatible = "fsl,imx35-wdt", "fsl,imx21-wdt";
 				reg = <0x53fdc000 0x4000>;
 				clocks = <&clks 74>;
-				clock-names = "";
 				interrupts = <55>;
 			};