ARM: mvebu: Add a 2 GHz fixed-clock on Armada 38x SoCs

Armada 38x SoCs have a 2 GHz fixed main PLL that is used to feed
other clocks. This commit adds a DT representation of this clock
through a fixed-clock compatible node.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Link: https://lkml.kernel.org/r/1394742273-5113-3-git-send-email-ezequiel.garcia@free-electrons.comSigned-off-by: Jason Cooper <jason@lakedaemon.net>

arch/arm/boot/dts/armada-38x.dtsi

@@ -341,6 +341,13 @@ mdio {
 	};
 
 	clocks {
+		/* 2 GHz fixed main PLL */
+		mainpll: mainpll {
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+			clock-frequency = <2000000000>;
+		};
+
 		/* 25 MHz reference crystal */
 		refclk: oscillator {
 			compatible = "fixed-clock";