ARM: dts: at91: smartkiz: Reference led node directly

Do it the simple way like for the other kizbox boards.  This will allow
renaming the led controller node name later without breaking things.

Signed-off-by: Alexander Dahl <post@lespocky.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201005203451.9985-5-post@lespocky.de
(cherry picked from commit 02e4626)
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

Author: LeSpocky

arch/arm/boot/dts/at91-smartkiz.dts

@@ -84,10 +84,8 @@
 	status = "okay";
 };
 
-&leds {
-	blue {
-		status = "okay";
-	};
+&led_blue {
+	status = "okay";
 };
 
 &adc0 {