ARM: shmobile: r8a73a4: Remove spurious dma-multiplexer base addresses

As there is no reg property the dma-multiplexer nodes should
not include @...
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a73a4.dtsi

@@ -122,7 +122,7 @@
 			     <0 57 IRQ_TYPE_LEVEL_HIGH>;
 	};
 
-	dmac: dma-multiplexer@0 {
+	dmac: dma-multiplexer {
 		compatible = "renesas,shdma-mux";
 		#dma-cells = <1>;
 		dma-channels = <20>;