fix(cpn): some trainer options not working

[pfeerick]

Fixes #5676

Summary of changes:

• allow Master/SBUS Module selection for more radios
• use correct enum for Master/Serial

[elecpower]

I too was working on a fix so kudos to you

[pfeerick]

np... one less item on that todo list ;) And that makes sense now... I was wondering WTH MASTER_BATT_COMP came from but see it was basically renamed some time ago... memory is on the fritz as I see now I wrote the issue about it 🤦‍♂️