ARM: dts: imx: add cooling-cells for cpufreq cooling device

Add #cooling-cells for i.MX6/7 SoCs for cpufreq cooling device usage.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6dl.dtsi

@@ -33,6 +33,7 @@ cpu@0 {
 				396000	1175000
 			>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			clocks = <&clks IMX6QDL_CLK_ARM>,
 				 <&clks IMX6QDL_CLK_PLL2_PFD2_396M>,
 				 <&clks IMX6QDL_CLK_STEP>,

arch/arm/boot/dts/imx6q.dtsi

@@ -38,6 +38,7 @@ cpu0: cpu@0 {
 				396000	1175000
 			>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			clocks = <&clks IMX6QDL_CLK_ARM>,
 				 <&clks IMX6QDL_CLK_PLL2_PFD2_396M>,
 				 <&clks IMX6QDL_CLK_STEP>,

arch/arm/boot/dts/imx6sl.dtsi

@@ -60,6 +60,7 @@ cpu@0 {
 				396000          1175000
 			>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			clocks = <&clks IMX6SL_CLK_ARM>, <&clks IMX6SL_CLK_PLL2_PFD2>,
 					<&clks IMX6SL_CLK_STEP>, <&clks IMX6SL_CLK_PLL1_SW>,
 					<&clks IMX6SL_CLK_PLL1_SYS>;

arch/arm/boot/dts/imx6sx.dtsi

@@ -79,6 +79,7 @@ cpu0: cpu@0 {
 				198000	    1175000
 			>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			clocks = <&clks IMX6SX_CLK_ARM>,
 				 <&clks IMX6SX_CLK_PLL2_PFD2>,
 				 <&clks IMX6SX_CLK_STEP>,

arch/arm/boot/dts/imx6ul.dtsi

@@ -62,6 +62,7 @@ cpu0: cpu@0 {
 			device_type = "cpu";
 			reg = <0>;
 			clock-latency = <61036>; /* two CLK32 periods */
+			#cooling-cells = <2>;
 			operating-points = <
 				/* kHz	uV */
 				696000	1275000

arch/arm/boot/dts/imx7d.dtsi

@@ -11,6 +11,7 @@ cpus {
 		cpu0: cpu@0 {
 			clock-frequency = <996000000>;
 			operating-points-v2 = <&cpu0_opp_table>;
+			#cooling-cells = <2>;
 		};
 
 		cpu1: cpu@1 {