Add Stop Decel and Quick Stop Decel parameters to Elmo Platinum Drive

[richardw347]

Quick PR to expose the Stop Decel (SD) and Quick Stop Decel (SD) parameters.

I'm working on an application which involves lifting a heavy load using a vertical axis with limit switches. It's very helpful to be able to set these deceleration parameters, especially SD which is used when a limit switch is hit.

I've tested this PR with our own platinum twitter drives, and I've also updated and tested all the epd test cases, except the network test as I don't have the beckoff el3602.

Also another note I didn't run a make format for this PR as it made quite a lot of other changes to files I didn't touch. Happy to submit a separate formatting PR.