Make sure to clear CBAUD before setting the baud and disable
input modifications.
Fix for #12162
This change removes input options that can modify the input data stream.
INLCR: map new line to carriage return
ICRNL: map carriage return to new line
IUCLC: map upper case to lower case
IGNCR: ignore carriage return
BRKINT: send SIGINT on serial break
this is the first step to using AP_RCProtocol for most (or all) RC
input on Linux boards. It also fixes a major bug on Disco where the
old SBUS decoder didn't use strict enough timing checks to filter out
bad frames when video capture is running. That led to erratic flight
mode changes and sometimes loss of control.
Andrew Tridgell
Daniel Magree