ARM: dts: rockchip: fix rk3288 iep-IOMMU interrupts property cells

The interrupts property in the iep-IOMMU node for the rk3288 dts file has a
spurious extra cell causing a dtc warning:

Warning (interrupts_property): interrupts size is (16), expected multiple of 12 in /iommu@ff900800

Remove the extra cell.
Signed-off-by: NRob Herring <robh@kernel.org>
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>

arch/arm/boot/dts/rk3288.dtsi

@@ -956,7 +956,7 @@
 	iep_mmu: iommu@ff900800 {
 		compatible = "rockchip,iommu";
 		reg = <0x0 0xff900800 0x0 0x40>;
-		interrupts = <GIC_SPI 17 IRQ_TYPE_LEVEL_HIGH 0>;
+		interrupts = <GIC_SPI 17 IRQ_TYPE_LEVEL_HIGH>;
 		interrupt-names = "iep_mmu";
 		#iommu-cells = <0>;
 		status = "disabled";