cmake: Add module WaffleCMocka

If waffle_build_tests, then this module imports the cmocka library built
in 'third_party/cmocka'. When configuring waffle, the module also
configures 'third_party/cmocka' by descending into the directory and
invoking cmake there.

All tests will eventrually be converted from using libwaffle_test to use
cmocka.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
core: Convert wcore_attrib_list_unittest to use cmocka

Convert it away from using libwaffle_test.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
core: Convert wcore_error_unittest to use cmocka

Convert it away from using libwaffle_test.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
core: Convert wcore_config_attrs_unittest to use cmocka

Convert it away from using libwaffle_test.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
core: Stop linking libwaffle_test into unittest executables

All unittests have been converted to use cmocka.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>