ARM: dts: imx6sx: Fix sdma node

Use the correct compatible string for sdma and also provide the sdma firmware
path.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>

arch/arm/boot/dts/imx6sx.dtsi

@@ -703,13 +703,15 @@ gpr: iomuxc-gpr@020e4000 {
 			};
 
 			sdma: sdma@020ec000 {
-				compatible = "fsl,imx6sx-sdma";
+				compatible = "fsl,imx6sx-sdma", "fsl,imx35-sdma";
 				reg = <0x020ec000 0x4000>;
 				interrupts = <GIC_SPI 2 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&clks IMX6SX_CLK_SDMA>,
 					 <&clks IMX6SX_CLK_SDMA>;
 				clock-names = "ipg", "ahb";
 				#dma-cells = <3>;
+				/* imx6sx reuses imx6q sdma firmware */
+				fsl,sdma-ram-script-name = "imx/sdma/sdma-imx6q.bin";
 			};
 		};