🩹 Fix LCD contrast with K8800 board

Marlin/src/pins/ramps/pins_K8800.h

@@ -105,9 +105,6 @@
   #define LCD_PINS_D6                         33
   #define LCD_PINS_D7                         31
 
-  #define LCD_CONTRAST_MIN                     0
-  #define LCD_CONTRAST_MAX                   100
-  #define LCD_CONTRAST_INIT                   30
   //#define LCD_SCREEN_ROTATE                180  // 0, 90, 180, 270
 
   #if IS_NEWPANEL