Emulate SERIAL_SUPPORT_INTERRUPT for UART_NATIVE_TTY, using a thread that
polls the tty and invokes the callback.
This allows interrupt-driven subsystems such as modbus to use a native tty,
which is useful for testing purposes.
Signed-off-by: Björn Stenberg <bjorn@haxx.se>
Split the native tty serial driver in a top and bottom to enable using it
with embedded libCs.
Signed-off-by: Marko Sagadin <marko.sagadin42@gmail.com>