at91sam9260.dtsi: add some labels

add labels to rtc, pinctrl and watchdog node.

This makes it possible to reference the nodes
from board dts files.

Signed-off-by: Heiko Schocher <hs@denx.de>
diff --git a/arch/arm/dts/at91sam9260.dtsi b/arch/arm/dts/at91sam9260.dtsi
index 476ad1d..800d96e 100644
--- a/arch/arm/dts/at91sam9260.dtsi
+++ b/arch/arm/dts/at91sam9260.dtsi
@@ -437,7 +437,7 @@
 				u-boot,dm-pre-reloc;
 			};
 
-			pinctrl@fffff400 {
+			pinctrl: pinctrl@fffff400 {
 				#address-cells = <1>;
 				#size-cells = <1>;
 				compatible = "atmel,at91rm9200-pinctrl", "simple-bus";
@@ -978,7 +978,7 @@
 				};
 			};
 
-			rtc@fffffd20 {
+			rtc: rtc@fffffd20 {
 				compatible = "atmel,at91sam9260-rtt";
 				reg = <0xfffffd20 0x10>;
 				interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
@@ -986,7 +986,7 @@
 				status = "disabled";
 			};
 
-			watchdog@fffffd40 {
+			watchdog: watchdog@fffffd40 {
 				compatible = "atmel,at91sam9260-wdt";
 				reg = <0xfffffd40 0x10>;
 				interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;