ARM: shmobile: r8a7779: Add Maximum CPU Frequency to DTS

Add 1GHz to the r8a7779 DTS to describe the maximum CPU frequency.

Based on work by Magnus dam for the r8a7740 SoC.

Cc: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7779.dtsi

@@ -26,21 +26,25 @@ cpu@0 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a9";
 			reg = <0>;
+			clock-frequency = <1000000000>;
 		};
 		cpu@1 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a9";
 			reg = <1>;
+			clock-frequency = <1000000000>;
 		};
 		cpu@2 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a9";
 			reg = <2>;
+			clock-frequency = <1000000000>;
 		};
 		cpu@3 {
 			device_type = "cpu";
 			compatible = "arm,cortex-a9";
 			reg = <3>;
+			clock-frequency = <1000000000>;
 		};
 	};