arm64: dts: berlin4ct: support cpuidle-dt

This patch adds an idle-states node to describe the berlin4ct idle
states and also adds references to the idle-states node in all CPU
nodes. After this patch cpuidle is enabled.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>

arch/arm64/boot/dts/marvell/berlin4ct.dtsi

@@ -68,6 +68,7 @@
 			device_type = "cpu";
 			reg = <0x0>;
 			enable-method = "psci";
+			cpu-idle-states = <&CPU_SLEEP_0>;
 		};
 
 		cpu1: cpu@1 {
@@ -75,6 +76,7 @@
 			device_type = "cpu";
 			reg = <0x1>;
 			enable-method = "psci";
+			cpu-idle-states = <&CPU_SLEEP_0>;
 		};
 
 		cpu2: cpu@2 {
@@ -82,6 +84,7 @@
 			device_type = "cpu";
 			reg = <0x2>;
 			enable-method = "psci";
+			cpu-idle-states = <&CPU_SLEEP_0>;
 		};
 
 		cpu3: cpu@3 {
@@ -89,6 +92,19 @@
 			device_type = "cpu";
 			reg = <0x3>;
 			enable-method = "psci";
+			cpu-idle-states = <&CPU_SLEEP_0>;
+		};
+
+		idle-states {
+			entry-method = "psci";
+			CPU_SLEEP_0: cpu-sleep-0 {
+				compatible = "arm,idle-state";
+				local-timer-stop;
+				arm,psci-suspend-param = <0x0010000>;
+				entry-latency-us = <75>;
+				exit-latency-us = <155>;
+				min-residency-us = <1000>;
+			};
 		};
 	};