MKS GEN v1.3/1.4 undef STAT_LED_*_PIN (#14644)

Marlin/src/pins/ramps/pins_MKS_GEN_13.h

   #undef SD_DETECT_PIN
   #undef BEEPER_PIN
   #undef KILL_PIN
+  #undef STAT_LED_RED_PIN
+  #undef STAT_LED_BLUE_PIN
 
   //
   // VIKI2 12-wire lead