Add missing chunk of code to enforce the lock-bits of termios.
Add missing chunk of code to enforce the lock-bits of termios.

This solves the problem where serial consoles suddenly required
DCD to be asserted.

Reported by:	Randy Bush <randy@psg.com>

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase