ARM: at91/dt: cosino define crystals frequencies

Define Cosino boards main and slow crystals frequencies.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/boot/dts/at91-cosino.dtsi

@@ -34,6 +34,14 @@
 			compatible = "atmel,osc", "fixed-clock";
 			clock-frequency = <12000000>;
 		};
+
+		slow_xtal {
+			clock-frequency = <32768>;
+		};
+
+		main_xtal {
+			clock-frequency = <12000000>;
+		};
 	};
 
 	ahb {