stmhal: Make pybstdio usable by other ports, and use it.
Now all ports can use pybstdio.c to provide sys.stdin/stdout/stderr, so long as they implement mp_hal_stdin_* and mp_hal_stdout_* functions.
esp8266/pybstdio.c
deleted
100644 → 0
esp8266/pybstdio.h
deleted
100644 → 0