Galil: Ensure the limit_at_home flag has been correctly set

As a user I would like the home indicator to be correct. The limit_at_home value has historically not always been set correctly. This will cause the axis to report being at home when on a limit. The value is now documented at https://github.com/ISISComputingGroup/ibex_developers_manual/wiki/Galil#configure-galil-crate-1

We should be able to write a script to confirm that the current values are correct by checking them against the homing routine that is being used.