ARM: dts: ls1021a: Use generic node name for DMA

DT spec expects generic DMA controller node name as "dma-controller" to
enable validations.
Signed-off-by: Kuldeep Singh <singh.kuldeep87k@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/ls1021a.dtsi

@@ -647,7 +647,7 @@ sai2: sai@2b60000 {
 			status = "disabled";
 		};
 
-		edma0: edma@2c00000 {
+		edma0: dma-controller@2c00000 {
 			#dma-cells = <2>;
 			compatible = "fsl,vf610-edma";
 			reg = <0x0 0x2c00000 0x0 0x10000>,