Initial changes to remove xud dependancies when compiling with NO_USB=1

module_usb_audio/audio_io/audio_io.xc

@@ -1048,8 +1048,10 @@ void SpdifTxWrapper(chanend c_spdif_tx)
 /* This function is a dummy version of the deliver thread that does not
    connect to the codec ports. It is used during DFU reset. */
 
+#if DFU
 [[distributable]]
 void DFUHandler(server interface i_dfu i, chanend ?c_user_cmd);
+#endif
 
 #pragma select handler
 void testct_byref(chanend c, int &returnVal)

module_usb_audio/audio_io/xua_audio.h

@@ -3,7 +3,9 @@
 
 #if __XC__
 
+#ifndef NO_USB
 #include "dfu_interface.h"
+#endif
 
 typedef interface audManage_if
 {