ARM: dts: imx: Align L2 cache-controller nodename with dtschema

Fix dtschema validator warnings like:
    l2-cache@a02000: $nodename:0:
        'l2-cache@a02000' does not match '^(cache-controller|cpu)(@[0-9a-f,]+)*$'
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx35.dtsi

@@ -59,7 +59,7 @@
 		interrupt-parent = <&avic>;
 		ranges;
 
-		L2: l2-cache@30000000 {
+		L2: cache-controller@30000000 {
 			compatible = "arm,l210-cache";
 			reg = <0x30000000 0x1000>;
 			cache-unified;

arch/arm/boot/dts/imx6qdl.dtsi

@@ -245,7 +245,7 @@
 			interrupt-parent = <&intc>;
 		};
 
-		L2: l2-cache@a02000 {
+		L2: cache-controller@a02000 {
 			compatible = "arm,pl310-cache";
 			reg = <0x00a02000 0x1000>;
 			interrupts = <0 92 IRQ_TYPE_LEVEL_HIGH>;

arch/arm/boot/dts/imx6sl.dtsi

@@ -126,7 +126,7 @@
 			interrupt-parent = <&intc>;
 		};
 
-		L2: l2-cache@a02000 {
+		L2: cache-controller@a02000 {
 			compatible = "arm,pl310-cache";
 			reg = <0x00a02000 0x1000>;
 			interrupts = <0 92 IRQ_TYPE_LEVEL_HIGH>;

arch/arm/boot/dts/imx6sll.dtsi

@@ -126,7 +126,7 @@
 			interrupt-parent = <&intc>;
 		};
 
-		L2: l2-cache@a02000 {
+		L2: cache-controller@a02000 {
 			compatible = "arm,pl310-cache";
 			reg = <0x00a02000 0x1000>;
 			interrupts = <GIC_SPI 92 IRQ_TYPE_LEVEL_HIGH>;

arch/arm/boot/dts/imx6sx.dtsi

@@ -179,7 +179,7 @@
 			interrupt-parent = <&intc>;
 		};
 
-		L2: l2-cache@a02000 {
+		L2: cache-controller@a02000 {
 			compatible = "arm,pl310-cache";
 			reg = <0x00a02000 0x1000>;
 			interrupts = <GIC_SPI 92 IRQ_TYPE_LEVEL_HIGH>;