Fix BQ_LCD_SMART_CONTROLLER pin compiler warnings

Marlin/pins_BQ_ZUM_MEGA_3D.h

 #undef PS_ON_PIN             // 12
 #define PS_ON_PIN         81 // External Power Supply
 
-#if ENABLED(BQ_LCD_SMART_CONTROLLER) // Most similar to REPRAP_DISCOUNT_SMART_CONTROLLER
-  #define KILL_PIN        41
-
-  #define BEEPER_PIN      37
-
-  #define BTN_EN1         31
-  #define BTN_EN2         33
-  #define BTN_ENC         35
-
-  #define LCD_PIN_BL      39
-  #define LCD_PINS_RS     16
-  #define LCD_PINS_ENABLE 17
-  #define LCD_PINS_D4     23
-
-  #define SD_DETECT_PIN   49
-#endif
-
 #if ENABLED(AUTO_BED_LEVELING_FEATURE)
   #undef Z_MIN_PIN
   #undef Z_MAX_PIN

Marlin/pins_RAMPS_14.h

 
 #define PS_ON_PIN          12
 
-#if ENABLED(REPRAP_DISCOUNT_SMART_CONTROLLER) || ENABLED(G3D_PANEL)
-  #define KILL_PIN         41
-#endif
-
 #if MB(RAMPS_14_EFF) || MB(RAMPS_13_EFF)
   #define HEATER_0_PIN      8
 #else
       #define BTN_ENC 35
 
       #define SD_DETECT_PIN 49
+      #define KILL_PIN 41
+
+      #if ENABLED(BQ_LCD_SMART_CONTROLLER)
+        #define LCD_PIN_BL 39
+      #endif
+
     #elif ENABLED(LCD_I2C_PANELOLU2)
       #define BTN_EN1 47  // reverse if the encoder turns the wrong way.
       #define BTN_EN2 43
 
       #if ENABLED(G3D_PANEL)
         #define SD_DETECT_PIN 49
+        #define KILL_PIN 41
       #else
         //        #define SD_DETECT_PIN -1  // Ramps doesn't use this
       #endif
   #define MISO_PIN         50
   #define MOSI_PIN         51
 #endif
-
-#ifndef KILL_PIN
-  //  #define KILL_PIN         -1
-#endif