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

Fix dtschema validator warnings like:
l2-cache-controller@80040000: $nodename:0:
'l2-cache-controller@80040000' does not match '^(cache-controller|cpu)(@[0-9a-f,]+)*$'

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Acked-by: Barry Song <[e-mail]>

arch/arm/boot/dts/prima2.dtsi

···
 		#size-cells = <1>;
 		ranges = <0x40000000 0x40000000 0x80000000>;
 
-		l2-cache-controller@80040000 {
+		cache-controller@80040000 {
 			compatible = "arm,pl310-cache";
 			reg = <0x80040000 0x1000>;
 			interrupts = <59>;