riscv: dts: fix the mpfs's reference clock frequency

The initial devicetree for PolarFire SoC incorrectly created a fixed
frequency clock in the devicetree to represent the msspll, but the
msspll is not a fixed frequency clock. The actual reference clock on a
board is either 125 or 100 MHz, 125 MHz in the case of the icicle kit.
Swap the incorrect representation of the msspll out for the actual
reference clock.

Fixes: dd4ee416a6 ("riscv: dts: Add device tree for Microchip Icicle Kit")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Reviewed-by: Padmarao Begari <padmarao.begari@microchip.com>

arch/riscv/dts/microchip-mpfs-icicle-kit.dts

@@ -54,6 +54,10 @@
 	};
 };
 
+&refclk {
+	clock-frequency = <125000000>;
+};
+
 &uart1 {
 	status = "okay";
 };

arch/riscv/dts/microchip-mpfs.dtsi

@@ -170,6 +170,11 @@
 		};
 	};
 
+	refclk: refclk {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+	};
+
 	soc {
 		#address-cells = <2>;
 		#size-cells = <2>;
@@ -225,16 +230,9 @@
 					&cpu4_intc HART_INT_M_EXT &cpu4_intc HART_INT_S_EXT>;
 		};
 
-		refclk: refclk {
-			compatible = "fixed-clock";
-			#clock-cells = <0>;
-			clock-frequency = <600000000>;
-			clock-output-names = "msspllclk";
-		};
-
 		clkcfg: clkcfg@20002000 {
 			compatible = "microchip,mpfs-clkcfg";
-			reg = <0x0 0x20002000 0x0 0x1000>;
+			reg = <0x0 0x20002000 0x0 0x1000>, <0x0 0x3E001000 0x0 0x1000>;
 			reg-names = "mss_sysreg";
 			clocks = <&refclk>;
 			#clock-cells = <1>;