refactor: Remove unimportant labels

Removed "label" properties which no longer have any function.

Labels are still used as layer names and as identifiers for sending
behaviors between sides of a split keyboard, so those have been left
alone for now.

app/boards/shields/nice_view/nice_view.overlay

@@ -8,7 +8,6 @@
     status = "okay";
     nice_view: ls0xx@0 {
         compatible = "sharp,ls0xx";
-        label = "DISPLAY";
         spi-max-frequency = <1000000>;
         reg = <0>;
         width = <160>;