ARM: shmobile: Update r8a7791 CPU freq to 1500MHz in DTS

The correct maximum CPU frequency for r8a7791 is 1500 MHz
so update the r8a7791 SoC DTS to reflect this.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7791.dtsi

@@ -37,14 +37,14 @@ cpu0: cpu@0 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a15";
 			reg = <0>;
-			clock-frequency = <1300000000>;
+			clock-frequency = <1500000000>;
 		};
 
 		cpu1: cpu@1 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a15";
 			reg = <1>;
-			clock-frequency = <1300000000>;
+			clock-frequency = <1500000000>;
 		};
 	};