ARM: dts: sama5d2: add clock property for uart1 node

Add clock property for uart1 node.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
diff --git a/arch/arm/dts/sama5d2.dtsi b/arch/arm/dts/sama5d2.dtsi
index a881d9e..d976fd4 100644
--- a/arch/arm/dts/sama5d2.dtsi
+++ b/arch/arm/dts/sama5d2.dtsi
@@ -600,6 +600,8 @@
 			uart1: serial@f8020000 {
 				compatible = "atmel,at91sam9260-usart";
 				reg = <0xf8020000 0x100>;
+				clocks = <&uart1_clk>;
+				clock-names = "usart";
 				status = "disabled";
 			};