tests: Fix tests using tpm2-abrmd by preventing concurrency

tests: Fix tests using tpm2-abrmd by preventing concurrency

The two tests test_tpm2_samples_create_tpmca and
test_tpm2_swtpm_localca_pkcs11 cannot complete successfully if run in
parallel. To solve this issue, introduce a dependency via the log files
to prevent parallel execution of the two test. We have to append the
.test suffix to their names to be able to do this.

docs:
https://www.gnu.org/software/automake/manual/html_node/Parallel-Test-Harness.html

Resolves issue #501, though the problem with stability of the tpm2 pkcs11
module is not resolved.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>