ARM: dts: rockchip: rk3xxx: fix L2 cache-controller nodename

A test with the command below gives for example this error:

arch/arm/boot/dts/rk3066a-bqcurie2.dt.yaml:
l2-cache-controller@10138000: $nodename:0:
'l2-cache-controller@10138000'
does not match '^(cache-controller|cpu)(@[0-9a-f,]+)*$'

Fix error by changing nodename to 'cache-controller'.

make ARCH=arm dtbs_check
DT_SCHEMA_FILES=Documentation/devicetree/bindings/arm/l2c2x0.yaml
Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Link: https://lore.kernel.org/r/20200316165453.3022-1-jbx6244@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm/boot/dts/rk3xxx.dtsi

@@ -91,7 +91,7 @@ gpu: gpu@10090000 {
 		status = "disabled";
 	};
 
-	L2: l2-cache-controller@10138000 {
+	L2: cache-controller@10138000 {
 		compatible = "arm,pl310-cache";
 		reg = <0x10138000 0x1000>;
 		cache-unified;