Fix compile error on MK3

Firmware/stepper.cpp

@@ -1563,7 +1563,7 @@ void EEPROM_read_st(int pos, uint8_t* value, uint8_t size)
 void st_current_init() //Initialize Digipot Motor Current
 {  
   uint8_t SilentMode = eeprom_read_byte((uint8_t*)EEPROM_SILENT);
-  if (SilentMode == 0xff) SilentMode = SILENT_MODE_POWER;
+  if (SilentMode == 0xff) SilentMode = 0; //set power to High Power (MK2.5) or Normal Power (MK3, unused)
   SilentModeMenu = SilentMode;
   #ifdef MOTOR_CURRENT_PWM_XY_PIN
     pinMode(MOTOR_CURRENT_PWM_XY_PIN, OUTPUT);