dts: vt8500: Correct reference clock on WM8850 SoCs

WM8850 SoCs use a 24Mhz reference clock for the PLLs but the SoC file
currently parents all PLLs to the 25Mhz reference clock.

This patch corrects the PLL parent clock references.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>

arch/arm/boot/dts/wm8850.dtsi

@@ -84,49 +84,49 @@ ref24: ref24M {
 				plla: plla {
 					#clock-cells = <0>;
 					compatible = "wm,wm8850-pll-clock";
-					clocks = <&ref25>;
+					clocks = <&ref24>;
 					reg = <0x200>;
 				};
 
 				pllb: pllb {
 					#clock-cells = <0>;
 					compatible = "wm,wm8850-pll-clock";
-					clocks = <&ref25>;
+					clocks = <&ref24>;
 					reg = <0x204>;
 				};
 
 				pllc: pllc {
 					#clock-cells = <0>;
 					compatible = "wm,wm8850-pll-clock";
-					clocks = <&ref25>;
+					clocks = <&ref24>;
 					reg = <0x208>;
 				};
 
 				plld: plld {
 					#clock-cells = <0>;
 					compatible = "wm,wm8850-pll-clock";
-					clocks = <&ref25>;
+					clocks = <&ref24>;
 					reg = <0x20c>;
 				};
 
 				plle: plle {
 					#clock-cells = <0>;
 					compatible = "wm,wm8850-pll-clock";
-					clocks = <&ref25>;
+					clocks = <&ref24>;
 					reg = <0x210>;
 				};
 
 				pllf: pllf {
 					#clock-cells = <0>;
 					compatible = "wm,wm8850-pll-clock";
-					clocks = <&ref25>;
+					clocks = <&ref24>;
 					reg = <0x214>;
 				};
 
 				pllg: pllg {
 					#clock-cells = <0>;
 					compatible = "wm,wm8850-pll-clock";
-					clocks = <&ref25>;
+					clocks = <&ref24>;
 					reg = <0x218>;
 				};