Unused fates switch that sets up defaults and influences namelist build

### Brief summary of bug

Unused fates switch that for some reason is used in namelists.

### General bug information

**CTSM version you are using:** ctsm5.4.039

**Does this bug cause significantly incorrect results in the model's science?** No

**Configurations affected:** Fates

### Details of bug

For whatever reason, there is still a switch:
https://github.com/ESCOMP/CTSM/blob/f1e0f2374f0c7da3b81cb91ce46853c36e4341d7/src/utils/clmfates_interfaceMod.F90#L76
That is not used anywhere inside or outside fates apart from in `ClmBuildNamelist.pm` and piped to controlMod

For whatever reason it is used as an attribute in bunch of namelist_defauls entries for fates switches.

### Important details of your setup / configuration so we can reproduce the bug

### Important output or errors that show the problem