Switch rtems workflows to generic-rtems

**Is your feature request related to a problem? Please describe.**
pc-rtems is not intended for generic use

**Describe the solution you'd like**
Switch to generic-rtems which is configurable and includes pc support

**Describe alternatives you've considered**
None

**Additional context**
Depends on https://github.com/nasa/osal/pull/1350

**Requester Info**
Jacob Hageman - NASA/GSFC
