changes to satisfy ufsatm and cesm requirements for pot temp and density from atm

[mvertens]

changes to satisfy ufsatm and cesm requirements for pot temp and density from atm

For detailed information about submitting Pull Requests (PRs) to the CICE-Consortium,
please refer to: https://github.com/CICE-Consortium/About-Us/wiki/Resource-Index#information-for-developers

PR checklist

• Short (1 sentence) summary of your PR:
  Rather than have calculations done in the CMEPS mediator, it was decided based on joint discussions with EMC that the cice6 noupc cap for cmeps should be able to adapt to the requirements of both UFSATM and CESM.
• Developer(s):
  Mariana Vertenstein, Denise Worthen
• Suggest PR reviewers from list in the column to the right.
• Please copy the PR test results link or provide a summary of testing completed below.
  • verified that running SMS_Vnuopc_Ld1.T62_g37.DTEST.cheyenne_intel remained bfb with respect to the origin cap.
• How much do the PR code changes differ from the unmodified code?
  • bit for bit
  • different at roundoff level
  • more substantial
• Does this PR create or have dependencies on Icepack or any other models?
  • Yes
  • No
• Does this PR add any new test cases?
  • Yes
  • No
• Is the documentation being updated? ("Documentation" includes information on the wiki or in the .rst files from doc/source/, which are used to create the online technical docs at https://readthedocs.org/projects/cice-consortium-cice/. A test build of the technical docs will be performed as part of the PR testing.)
  • Yes
  • No, does the documentation need to be updated at a later time?
    • Yes
    • No
• Please provide any additional information or relevant details below:
  None