add ENCODER_PULSES_PER_STEP

Marlin/ultralcd.cpp

 
 #if !defined(LCD_I2C_VIKI)
   #define ENCODER_STEPS_PER_MENU_ITEM 5
+  #define ENCODER_PULSES_PER_STEP 1
 #else
   #define ENCODER_STEPS_PER_MENU_ITEM 2 // VIKI LCD rotary encoder uses a different number of steps per rotation
 #endif
         		reprapworld_keypad_move_home();
         	}
 		#endif
-        if (encoderDiff)
+        if (abs(encoderDiff) >= ENCODER_PULSES_PER_STEP)
         {
             lcdDrawUpdate = 1;
-            encoderPosition += encoderDiff;
+            encoderPosition += encoderDiff / ENCODER_PULSES_PER_STEP;
             encoderDiff = 0;
             timeoutToStatus = millis() + LCD_TIMEOUT_TO_STATUS;
         }