Debug coverage update

Created by: silabs-robin

Coverage class updated to new controller.

Debug coverage is re-enabled (upon COV=1), and covergroups have been slightly updated. In addition, unused signals were removed from the interface and some signals got updated. (There are also a few lines of whitespace fixes that I couldn't resist.)

Both formal and simulation tests are passing (ps, the cov model itself is not used in formal). I synced with upstream cv32e40x/dev and resolved the conflicts. On the "debug_test" it shows 90.61%, but I have not tried to merge coverage results from several other tests. @silabs-oysteink I think your eyes would be valuable on the assertions file and the tb connections.