ARM: dts: at91: Fix ADC trigger nodes

The triggers don't need a reg property, remove it when prenset. Also remove
the unit-address from their name.

This solves:
Warning (unit_address_vs_reg): Node /ahb/apb/adc@fc034000/trigger@0 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /ahb/apb/adc@fc034000/trigger@1 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /ahb/apb/adc@fc034000/trigger@2 has a unit name, but no reg property
Warning (unit_address_vs_reg): Node /ahb/apb/adc@fc034000/trigger@3 has a unit name, but no reg property

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

arch/arm/boot/dts/sama5d4.dtsi

@@ -1226,22 +1226,22 @@
 				atmel,adc-ts-pressure-threshold = <10000>;
 				status = "disabled";
 
-				trigger@0 {
+				trigger0 {
 					trigger-name = "external-rising";
 					trigger-value = <0x1>;
 					trigger-external;
 				};
-				trigger@1 {
+				trigger1 {
 					trigger-name = "external-falling";
 					trigger-value = <0x2>;
 					trigger-external;
 				};
-				trigger@2 {
+				trigger2 {
 					trigger-name = "external-any";
 					trigger-value = <0x3>;
 					trigger-external;
 				};
-				trigger@3 {
+				trigger3 {
 					trigger-name = "continuous";
 					trigger-value = <0x6>;
 				};