Make the library compatible with both API and non API cores (#35)

Fixes arduino/ArduinoCore-samd#578

Author: facchinm

src/ArduinoLowPower.h

@@ -18,6 +18,12 @@
 
 #define RTC_ALARM_WAKEUP	0xFF
 
+#ifdef ARDUINO_API_VERSION
+using irq_mode = PinStatus;
+#else
+using irq_mode = uint32_t;
+#endif
+
 //typedef void (*voidFuncPtr)( void ) ;
 typedef void (*onOffFuncPtr)( bool ) ;
 
@@ -59,7 +65,7 @@ class ArduinoLowPowerClass {
 			deepSleep((uint32_t)millis);
 		}
 
-		void attachInterruptWakeup(uint32_t pin, voidFuncPtr callback, uint32_t mode);
+		void attachInterruptWakeup(uint32_t pin, voidFuncPtr callback, irq_mode mode);
 
 		#ifdef BOARD_HAS_COMPANION_CHIP
 		void companionLowPowerCallback(onOffFuncPtr callback) {

src/samd/ArduinoLowPower.cpp

@@ -1,7 +1,6 @@
 #if defined(ARDUINO_ARCH_SAMD)
 
 #include "ArduinoLowPower.h"
-#include "WInterrupts.h"
 
 static void configGCLK6()
 {
@@ -72,15 +71,15 @@ void ArduinoLowPowerClass::deepSleep(uint32_t millis) {
 void ArduinoLowPowerClass::setAlarmIn(uint32_t millis) {
 
 	if (!rtc.isConfigured()) {
-		attachInterruptWakeup(RTC_ALARM_WAKEUP, NULL, 0);
+		attachInterruptWakeup(RTC_ALARM_WAKEUP, NULL, (irq_mode)0);
 	}
 
 	uint32_t now = rtc.getEpoch();
 	rtc.setAlarmEpoch(now + millis/1000);
 	rtc.enableAlarm(rtc.MATCH_YYMMDDHHMMSS);
 }
 
-void ArduinoLowPowerClass::attachInterruptWakeup(uint32_t pin, voidFuncPtr callback, uint32_t mode) {
+void ArduinoLowPowerClass::attachInterruptWakeup(uint32_t pin, voidFuncPtr callback, irq_mode mode) {
 
 	if (pin > PINS_COUNT) {
 		// check for external wakeup sources