MPS Reader Tests: Test basic feed-get-commit-reclaim cycle

This commit adds an MPS unit test suite `test_suite_mps` which will
subsequently be populated with unit tests for all components of MPS.

As a start, a test case

```
   mbedtls_mps_reader_no_pausing_single_step_single_round()
```

is added which exercises the most basic usage of the MPS reader
component; see the test case description for more details.

Signed-off-by: Hanno Becker <hanno.becker@arm.com>
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index c141704..049b130 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -134,6 +134,7 @@
 add_test_suite(mdx)
 add_test_suite(memory_buffer_alloc)
 add_test_suite(mpi)
+add_test_suite(mps)
 add_test_suite(net)
 add_test_suite(nist_kw)
 add_test_suite(oid)