include Stream.h & core_pins.h

needed for DEC and other Arduino stuff that's expected

include/usbhost/usbhost.h

 #define USB_HOST_TEENSY36_
 
 #include <stdint.h>
+#include <core/Stream.h>
+#include <core/core_pins.h>
 
 #if !defined(__MK66FX1M0__) && !defined(__IMXRT1052__) && !defined(__IMXRT1062__)
 #error "USBHost_t36 only works with Teensy 3.6 or Teensy 4.x.  Please select it in Tools > Boards"