tinyusb: add 'extern C' bit to tusb_console.h
tinyusb: add 'extern C' bit to tusb_console.h

Public headers need the "if __cplusplus, extern C" boilerplate. Otherwise, C++
sources which include the header will look for a name-mangled symbol and fail
at link time.

Closes https://github.com/espressif/esp-idf/pull/6455
Closes IDFGH-4641

espressif/esp-idf,espressif/esp-idf,espressif/esp-idf,espressif/esp-idf