async_spdif_input.h added to audio header

Audio.h

 #include "analyze_notefreq.h"
 #include "analyze_peak.h"
 #include "analyze_rms.h"
+#include "async_input_spdif3.h"
 #include "control_sgtl5000.h"
 #include "control_wm8731.h"
 #include "control_ak4558.h"

examples/HardwareTesting/PassThroughAsyncSpdif/PassThroughAsyncSpdif.ino

 
-#include "output_spdif3.h"
-#include "async_input_spdif3.h"
 #include <Audio.h>
-#include <SerialFlash.h>
-
-
 
 AudioOutputSPDIF3   spdifOut;
 AsyncAudioInputSPDIF3     spdifIn(true, true, 100, 20);	//dither = true, noiseshaping = true, anti-aliasing attenuation=100dB, minimum resampling filter length=20