Expand RAMP case light possibilities

Pin 6 is only used by servos when 2 or more of them are used

Marlin/src/pins/pins_RAMPS.h

@@ -264,7 +264,7 @@
 #endif
 
 #if ENABLED(CASE_LIGHT_ENABLE) && !PIN_EXISTS(CASE_LIGHT) && !defined(SPINDLE_LASER_ENABLE_PIN)
-  #if !defined(NUM_SERVOS) || NUM_SERVOS == 0 // try to use servo connector first
+  #if !defined(NUM_SERVOS) || NUM_SERVOS <= 1 // try to use servo connector first
     #define CASE_LIGHT_PIN   6      // MUST BE HARDWARE PWM
   #elif !(ENABLED(ULTRA_LCD) && ENABLED(NEWPANEL) \
       && (ENABLED(PANEL_ONE) || ENABLED(VIKI2) || ENABLED(miniVIKI) || ENABLED(MINIPANEL) || ENABLED(REPRAPWORLD_KEYPAD)))  // try to use AUX 2