arm64: dts: marvell: armada-37xx: add nodes allowing cpufreq support

In order to be able to use cpu freq, we need to associate a clock to each
CPU and to expose the power management registers.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

arch/arm64/boot/dts/marvell/armada-372x.dtsi

@@ -56,6 +56,7 @@ cpu@1 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a53","arm,armv8";
 			reg = <0x1>;
+			clocks = <&nb_periph_clk 16>;
 			enable-method = "psci";
 		};
 	};

arch/arm64/boot/dts/marvell/armada-37xx.dtsi

@@ -65,6 +65,7 @@ cpu@0 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a53", "arm,armv8";
 			reg = <0>;
+			clocks = <&nb_periph_clk 16>;
 			enable-method = "psci";
 		};
 	};
@@ -234,6 +235,12 @@ uart2_pins: uart2-pins {
 				};
 			};
 
+			nb_pm: syscon@14000 {
+				compatible = "marvell,armada-3700-nb-pm",
+					     "syscon";
+				reg = <0x14000 0x60>;
+			};
+
 			pinctrl_sb: pinctrl@18800 {
 				compatible = "marvell,armada3710-sb-pinctrl",
 					     "syscon", "simple-mfd";