arm64: zynqmp: Fix the si570 clock frequency on zcu111

The si570 clock frequency should be 156.25MHz as per datasheet.
Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm64/boot/dts/xilinx/zynqmp-zcu111-revA.dts

@@ -317,7 +317,7 @@ si570_2: clock-generator@5d { /* USER MGT SI570 - u49 */
 				reg = <0x5d>;
 				temperature-stability = <50>;
 				factory-fout = <156250000>;
-				clock-frequency = <148500000>;
+				clock-frequency = <156250000>;
 				clock-output-names = "si570_mgt";
 			};
 		};