ARM: dts: add board specific fixed rate clock nodes for Exynos based platforms

The clock frequency of xxti and xusbxti clocks is dependent on the
frequency of the on-board oscillator that is used to generate these
clocks. So allow the frequency of these clocks to be specfied from
device tree.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/boot/dts/exynos4210-origen.dts

@@ -127,4 +127,16 @@
 			linux,default-trigger = "heartbeat";
 		};
 	};
+
+	fixed-rate-clocks {
+		xxti {
+			compatible = "samsung,clock-xxti";
+			clock-frequency = <0>;
+		};
+
+		xusbxti {
+			compatible = "samsung,clock-xusbxti";
+			clock-frequency = <24000000>;
+		};
+	};
 };