Move Assertions currently in the "tb" directory to their own "assertion" directory.

[DBees]

Currently, many of the assertions for CV32E20 are in modules in the cv32e20/tb/uvmt directory (example). This creates a cluttered directory which mixes procedural code and assertions.

This task is complete when all assertion modules in cv32e20/tb/uvmt as moved to a new directory cv32e20/tb/assertions. The manifest files will also need to be updated. See cv32e40s for an example.

[MikeOpenHWGroup]

The manifest that will need to be modified is uvmt_cv32e20.flist. Have a look at uvmt_cv32e40s_tb_files.flist for a working example.

[eladawy88]

The required modification are done in the following pull request.
openhwgroup/cv32e20-dv#4