ARM: dts: imx6sl: add baud clock and clock-names for ssi

Baud clock is used for bit clock generation in master mode. Ipg clock
is peripheral clock and peripheral access clock.
Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>

arch/arm/boot/dts/imx6sl.dtsi

@@ -231,7 +231,9 @@ ssi1: ssi@02028000 {
 							"fsl,imx51-ssi";
 					reg = <0x02028000 0x4000>;
 					interrupts = <0 46 IRQ_TYPE_LEVEL_HIGH>;
-					clocks = <&clks IMX6SL_CLK_SSI1>;
+					clocks = <&clks IMX6SL_CLK_SSI1_IPG>,
+						 <&clks IMX6SL_CLK_SSI1>;
+					clock-names = "ipg", "baud";
 					dmas = <&sdma 37 1 0>,
 					       <&sdma 38 1 0>;
 					dma-names = "rx", "tx";
@@ -245,7 +247,9 @@ ssi2: ssi@0202c000 {
 							"fsl,imx51-ssi";
 					reg = <0x0202c000 0x4000>;
 					interrupts = <0 47 IRQ_TYPE_LEVEL_HIGH>;
-					clocks = <&clks IMX6SL_CLK_SSI2>;
+					clocks = <&clks IMX6SL_CLK_SSI2_IPG>,
+						 <&clks IMX6SL_CLK_SSI2>;
+					clock-names = "ipg", "baud";
 					dmas = <&sdma 41 1 0>,
 					       <&sdma 42 1 0>;
 					dma-names = "rx", "tx";
@@ -259,7 +263,9 @@ ssi3: ssi@02030000 {
 							"fsl,imx51-ssi";
 					reg = <0x02030000 0x4000>;
 					interrupts = <0 48 IRQ_TYPE_LEVEL_HIGH>;
-					clocks = <&clks IMX6SL_CLK_SSI3>;
+					clocks = <&clks IMX6SL_CLK_SSI3_IPG>,
+						 <&clks IMX6SL_CLK_SSI3>;
+					clock-names = "ipg", "baud";
 					dmas = <&sdma 45 1 0>,
 					       <&sdma 46 1 0>;
 					dma-names = "rx", "tx";