reworked patch to meet ivanseidel suggestions

Author: ppescher

DueTimer.cpp

@@ -43,12 +43,12 @@ const DueTimer::Timer DueTimer::Timers[NUM_TIMERS] = {
 #else
 	void (*DueTimer::callbacks[NUM_TIMERS])() = {};
 #endif
-double DueTimer::_frequency[NUM_TIMERS] = {
-  -1,-1,-1,-1,-1,-1,
+		
 #if NUM_TIMERS > 6
-  -1,-1,-1
+double DueTimer::_frequency[NUM_TIMERS] = {-1,-1,-1,-1,-1,-1,-1,-1,-1};
+#else
+double DueTimer::_frequency[NUM_TIMERS] = {-1,-1,-1,-1,-1,-1};
 #endif
-  };
 
 /*
 	Initializing all timers, so you can use them like this: Timer0.start();

DueTimer.h

@@ -7,13 +7,13 @@
   Released into the public domain.
 */
 
-#ifdef __arm__
+#include "Arduino.h"
+
+#if defined(_SAM3XA_)
 
 #ifndef DueTimer_h
 #define DueTimer_h
 
-#include "Arduino.h"
-
 #include <inttypes.h>
 
 /*