Add tone support for Due (#9807)

Marlin/src/HAL/HAL_DUE/HAL_Due.h

@@ -157,11 +157,17 @@ void HAL_enable_AdcFreerun(void);
 /**
  * Pin Map
  */
-
 #define GET_PIN_MAP_PIN(index) index
 #define GET_PIN_MAP_INDEX(pin) pin
 #define PARSED_PIN_INDEX(code, dval) parser.intval(code, dval)
 
+/**
+ * Tone
+ */
+void toneInit();
+void tone(const pin_t _pin, const unsigned int frequency, const unsigned long duration=0);
+void noTone(const pin_t _pin);
+
 // Enable hooks into idle and setup for USB stack
 #define HAL_IDLETASK 1
 #define HAL_INIT 1