ARM: shmobile: r8a7740 dtsi: Add L2 cache-controller node

Add the missing L2 cache-controller node, and link the CPU node to it.
This will allow migration to the generic l2c OF initialization.

The L2 cache is an ARM L2C-310 (r3p1-150rel0), of size 256 KiB (32 KiB x
8 ways).
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7740.dtsi

@@ -26,6 +26,7 @@ cpu@0 {
 			reg = <0x0>;
 			clock-frequency = <800000000>;
 			power-domains = <&pd_a3sm>;
+			next-level-cache = <&L2>;
 		};
 	};
 
@@ -37,6 +38,18 @@ gic: interrupt-controller@c2800000 {
 		      <0xc2000000 0x1000>;
 	};
 
+	L2: cache-controller {
+		compatible = "arm,pl310-cache";
+		reg = <0xf0100000 0x1000>;
+		interrupts = <0 84 IRQ_TYPE_LEVEL_HIGH>;
+		power-domains = <&pd_a3sm>;
+		arm,data-latency = <3 3 3>;
+		arm,tag-latency = <2 2 2>;
+		arm,shared-override;
+		cache-unified;
+		cache-level = <2>;
+	};
+
 	dbsc3: memory-controller@fe400000 {
 		compatible = "renesas,dbsc3-r8a7740";
 		reg = <0xfe400000 0x400>;