ARC: [plat-axs10x]: use pgu pll instead of fixed clock

Use PLL driver instead of fixed-clock for PGU pixel clock.
That allows us to support wider range of graphic modes.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/boot/dts/axc001.dtsi

@@ -28,6 +28,12 @@ core_clk: core_clk {
 			clock-frequency = <750000000>;
 		};
 
+		input_clk: input-clk {
+			#clock-cells = <0>;
+			compatible = "fixed-clock";
+			clock-frequency = <33333333>;
+		};
+
 		core_intc: arc700-intc@cpu {
 			compatible = "snps,arc700-intc";
 			interrupt-controller;

arch/arc/boot/dts/axs10x_mb.dtsi

@@ -61,12 +61,13 @@ mmcclk: mmcclk {
 				clock-frequency = <25000000>;
 				#clock-cells = <0>;
 			};
+		};
 
-			pguclk: pguclk {
-				#clock-cells = <0>;
-				compatible = "fixed-clock";
-				clock-frequency = <74250000>;
-			};
+		pguclk: pguclk@10080 {
+			compatible = "snps,axs10x-pgu-pll-clock";
+			reg = <0x10080 0x10>, <0x110 0x10>;
+			#clock-cells = <0>;
+			clocks = <&input_clk>;
 		};
 
 		gmac: ethernet@18000 {