docs: Remove label property from documentation

docs/docs/features/backlight.md

@@ -242,7 +242,6 @@ Add each of your LEDs to the backlight node in the same manner as for one LED, u
 ```dts
 backlight: pwmleds {
     compatible = "pwm-leds";
-    label = "Backlight LEDs";
     pwm_led_0: pwm_led_0 {
         pwms = <&pwm0 0 PWM_MSEC(10) PWM_POLARITY_NORMAL>;
     };

docs/docs/features/battery.md

@@ -34,7 +34,6 @@ Once you have the sensor driver defined, add a `zmk,battery` property to the `ch
 
     vbatt: vbatt {
         compatible = "zmk,battery-nrf-vddh";
-        label = "VBATT";
     };
 }
 ```

docs/docs/features/underglow.md

@@ -98,7 +98,6 @@ Here's an example on a definition that uses P0.06:
 
   led_strip: ws2812@0 {
     compatible = "worldsemi,ws2812-spi";
-    label = "WS2812";
 
     /* SPI */
     reg = <0>; /* ignored, but necessary for SPI bindings */
@@ -142,7 +141,6 @@ Here's another example for a non-nRF52 board on `spi3`:
 
   led_strip: ws2812@0 {
     compatible = "worldsemi,ws2812-spi";
-    label = "WS2812";
 
     /* SPI */
     reg = <0>;