bugfix: add Crocus to CMake files

[scrasmussen]

TYPE: bugfix

KEYWORDS: bugfix, CMake, Crocus

SOURCE: Soren Rasmussen, NCAR

DESCRIPTION OF CHANGES: Added Crocus filenames to the appropriate CMake files.

ISSUE: Fixes #610

TESTS CONDUCTED: CMake builds, runs with Croton

Checklist

• [X] Closes issue #610 (An issue must exist or be created to be closed. The issue describes and documents the problem and general solution, the PR describes the technical details of the solution.)
• [ ] Tests added (unit tests and/or regression/integration tests)
• [X] Backwards compatible
• [ ] Requires new files? If so, how to generate them.
• [ ] Documentation included
• [ ] Short description in the Development section of NEWS.md

[rcabell]

Non-model changes; will merge with single review.