Clean up logic in config_pes.xml

### Description of the issue:

We typically define pe layouts in [cime_config/config_pes.xml](https://github.com/ESCOMP/POP2-CESM/blob/29e3a8d/cime_config/config_pes.xml) to match the regex `POP2[^%]` for non-ecosystem compsets and `POP2%ECO` for compsets with the ecosystem enabled. If we introduce a compset to use `POP2%ABIO-DIC` or `POP2%ABIO-DIC%ECO`, neither of the two `compset` attributes will match.

### Version:
- CESM: latest
- POP2: latest

### Machine/Environment Description:

`cheyenne` and `hobart` are currently the only machines specified in `config_pes.xml`

### Any xml/namelist changes or SourceMods:

no