arm64: zynqmp: Add L2 cache nodes

Describe SoC L2 cache hierarchy.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/130e5a6acbee94809b63a61cde5450fbff88cc9c.1685964230.git.michal.simek@amd.com

arch/arm64/boot/dts/xilinx/zynqmp.dtsi

@@ -33,6 +33,7 @@ cpu0: cpu@0 {
 			operating-points-v2 = <&cpu_opp_table>;
 			reg = <0x0>;
 			cpu-idle-states = <&CPU_SLEEP_0>;
+			next-level-cache = <&L2>;
 		};
 
 		cpu1: cpu@1 {
@@ -42,6 +43,7 @@ cpu1: cpu@1 {
 			reg = <0x1>;
 			operating-points-v2 = <&cpu_opp_table>;
 			cpu-idle-states = <&CPU_SLEEP_0>;
+			next-level-cache = <&L2>;
 		};
 
 		cpu2: cpu@2 {
@@ -51,6 +53,7 @@ cpu2: cpu@2 {
 			reg = <0x2>;
 			operating-points-v2 = <&cpu_opp_table>;
 			cpu-idle-states = <&CPU_SLEEP_0>;
+			next-level-cache = <&L2>;
 		};
 
 		cpu3: cpu@3 {
@@ -60,6 +63,13 @@ cpu3: cpu@3 {
 			reg = <0x3>;
 			operating-points-v2 = <&cpu_opp_table>;
 			cpu-idle-states = <&CPU_SLEEP_0>;
+			next-level-cache = <&L2>;
+		};
+
+		L2: l2-cache {
+			compatible = "cache";
+			cache-level = <2>;
+			cache-unified;
 		};
 
 		idle-states {