ARM: dts: lpc18xx: add dmamux node

Add node for the DMA multiplexer placed in front of the PL080 DMA
controller on lpc18xx/43xx devices.
Signed-off-by: Joachim Eastwood <manabian@gmail.com>

arch/arm/boot/dts/lpc18xx.dtsi

@@ -171,6 +171,13 @@ usb0_otg_phy: phy@004 {
 				clocks = <&ccu1 CLK_USB0>;
 				#phy-cells = <0>;
 			};
+
+			dmamux: dma-mux@11c {
+				compatible = "nxp,lpc1850-dmamux";
+				#dma-cells = <3>;
+				dma-requests = <64>;
+				dma-masters = <&dmac>;
+			};
 		};
 
 		cgu: clock-controller@40050000 {