Fixed warnings

cores/arduino/USB/samd21_host.c

@@ -22,9 +22,9 @@
 #include <string.h>
 
 #include "../Arduino.h"
+#include "../wiring_private.h"
 #include "USB_host.h"
 #include "samd21_host.h"
-#include "wiring_digital.h"
 
 #define HOST_DEFINED
 #ifdef HOST_DEFINED

cores/arduino/WInterrupts.c

@@ -17,6 +17,7 @@
 */
 
 #include "Arduino.h"
+#include "wiring_private.h"
 
 #include <string.h>
 

cores/arduino/wiring_analog.c

@@ -17,6 +17,7 @@
 */
 
 #include "Arduino.h"
+#include "wiring_private.h"
 
 #ifdef __cplusplus
 extern "C" {

cores/arduino/wiring_private.c

@@ -16,7 +16,7 @@
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#include "WVariant.h"
+#include "Arduino.h"
 #include "wiring_private.h"
 
 int pinPeripheral( uint32_t ulPin, EPioType ulPeripheral )