t4240/dts: Enable third elo3 DMA engine support

T4240 has a third DMA engine controller, so add the corresponding DMA
node into the dts file.

Signed-off-by: Chunhe Lan <Chunhe.Lan@freescale.com>
Cc: Scott Wood <scottwood@freescale.com>
[scottwood@freescale.com: reword commit message]
Signed-off-by: Scott Wood <scottwood@freescale.com>

arch/powerpc/boot/dts/fsl/t4240si-post.dtsi

@@ -476,6 +476,7 @@
 
 /include/ "elo3-dma-0.dtsi"
 /include/ "elo3-dma-1.dtsi"
+/include/ "elo3-dma-2.dtsi"
 
 /include/ "qoriq-espi-0.dtsi"
 	spi@110000 {

arch/powerpc/boot/dts/fsl/t4240si-pre.dtsi

@@ -57,6 +57,7 @@
 		pci3 = &pci3;
 		dma0 = &dma0;
 		dma1 = &dma1;
+		dma2 = &dma2;
 		sdhc = &sdhc;
 	};