I am another cmocka user. The answer to your question (as I understand it) is no. You must declare each test and then add it to a list before you invoke cmocka.
For my projects, I have written some compiler specific macros that will do the registration for you, so it is possible to work around it.
Trying to sign up; did not receive a confirmation email after several minutes now.
cmocka looks quite interesting! I'm with a company that is unfortunately locked into an older C standard, and I would love to have mocking available.
Haven't dug into cmocka yet; are tests and test suites self-registering?