fix includes to match package/deps layout

src/spi/SPI.cpp

  * published by the Free Software Foundation.
  */
 
-#include "SPI.h"
-#include "pins_arduino.h"
+#include "./SPI.h"
+#include <core/pins_arduino.h>
 
 //#define DEBUG_DMA_TRANSFERS
 

src/spi/SPI.h

 #ifndef _SPI_H_INCLUDED
 #define _SPI_H_INCLUDED
 
-#include <Arduino.h>
+#include <core/Arduino.h>
 
 #if defined(__arm__) && defined(TEENSYDUINO)
-#if defined(__has_include) && __has_include(<EventResponder.h>)
+#if defined(__has_include) && __has_include(<core/EventResponder.h>)
 // SPI_HAS_TRANSFER_ASYNC - Defined to say that the SPI supports an ASYNC version
 // of the SPI_HAS_TRANSFER_BUF
 #define SPI_HAS_TRANSFER_ASYNC 1
-#include <DMAChannel.h>
-#include <EventResponder.h>
+#include <core/DMAChannel.h>
+#include <core/EventResponder.h>
 #endif
 #endif