ARM: at91/dt: define sam9x5 clocks

Define sam9x5 clocks in sam9x5 dt files and make use of them in peripheral
definitions.

Signed-off-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
diff --git a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
index 6801106..140217a5 100644
--- a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
+++ b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
@@ -42,12 +42,23 @@
 				};
 			};
 
+			pmc: pmc@fffffc00 {
+				periphck {
+					usart3_clk: usart3_clk {
+						#clock-cells = <0>;
+						reg = <8>;
+					};
+				};
+			};
+
 			usart3: serial@f8028000 {
 				compatible = "atmel,at91sam9260-usart";
 				reg = <0xf8028000 0x200>;
 				interrupts = <8 IRQ_TYPE_LEVEL_HIGH 5>;
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_usart3>;
+				clocks = <&usart3_clk>;
+				clock-names = "usart";
 				status = "disabled";
 			};
 		};