ARM: Orion: Add arch support needed for I2C via DT.

The MV64XXX I2C driver needs a clock in order to calculate the baud
rate factors. So add an clk to the clk tree. Also add the base DT
properties for kirkwood devices.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>

Conflicts:
	arch/arm/mach-kirkwood/common.c

arch/arm/boot/dts/kirkwood.dtsi

@@ -82,5 +82,15 @@
 			/* set partition map and/or chip-delay in board dts */
 			status = "disabled";
 		};
+
+		i2c@11000 {
+			compatible = "marvell,mv64xxx-i2c";
+			reg = <0x11000 0x20>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			interrupts = <29>;
+			clock-frequency = <100000>;
+			status = "disabled";
+		};
 	};
 };