Remove redundant KC_TRNS and KC_NO fillers in default keymaps (#5152)

keyboards/phantom/keymaps/default/keymap.c

@@ -15,9 +15,6 @@
  */
 #include QMK_KEYBOARD_H
 
-// Helpful defines
-#define _______ KC_TRNS
-
 // Each layer gets a name for readability, which is then used in the keymap matrix below.
 // The underscores don't mean anything - you can have a layer called STUFF or any other name.
 // Layer names don't all need to be of the same length, obviously, and you can also skip them