ARM: dts: imx: correct sdma compatbile for imx6sl and imx6sx

The SDMA on imx6sl and imx6sx is more compatible with imx6q one than
imx35.  Let's use "fsl,imx6q-sdma" instead of "fsl,imx35-sdma", so that
SDMA ROM script on imx6sl and imx6sx can work for audio driver just like
the case of imx6q.
Reported-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NShawn Guo <shawn.guo@freescale.com>
Acked-by: NRobin Gong <yibin.gong@freescale.com>

arch/arm/boot/dts/imx6sl.dtsi

@@ -608,7 +608,7 @@
 			};
 
 			sdma: sdma@020ec000 {
-				compatible = "fsl,imx6sl-sdma", "fsl,imx35-sdma";
+				compatible = "fsl,imx6sl-sdma", "fsl,imx6q-sdma";
 				reg = <0x020ec000 0x4000>;
 				interrupts = <0 2 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&clks IMX6SL_CLK_SDMA>,

arch/arm/boot/dts/imx6sx.dtsi

@@ -706,7 +706,7 @@
 			};
 
 			sdma: sdma@020ec000 {
-				compatible = "fsl,imx6sx-sdma", "fsl,imx35-sdma";
+				compatible = "fsl,imx6sx-sdma", "fsl,imx6q-sdma";
 				reg = <0x020ec000 0x4000>;
 				interrupts = <GIC_SPI 2 IRQ_TYPE_LEVEL_HIGH>;
 				clocks = <&clks IMX6SX_CLK_SDMA>,