 Fix on USB-CDC 1200bps-touch reset condition
 Fix on USB-CDC 1200bps-touch reset condition

Some serial libraries opens the serial port BEFORE setting the baudrate.
This patch allows finer control on the reset condition, since it's
checked on open/close (DTR) AND on serial port parameter change.

MickMad/ArduinoCore-samd,MickMad/ArduinoCore-samd