Extend LIBUSB_API_VERSION check
The define exists since 1.0.13, so to compensate for older also
check if the variable is defined.
#include "libusb_udevice.h"
-#if LIBUSB_API_VERSION < 0x01000102
+#if !defined(LIBUSB_API_VERSION) || (LIBUSB_API_VERSION < 0x01000102)
#define LIBUSB_HOTPLUG_NO_FLAGS 0
#endif
