[Bluetooth] Use non-canonical TTY by default for RFCOMM

While the RFCOMM TTY emulation can act like a real serial port, in
reality it is not used like this. So to not mess up stupid applications,
use the non-canonical mode by default.

Signed-off-by: Denis Kenzior <denis.kenzior@trolltech.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>