C3: build and run unit tests

Enable building and running of unit tests in CI for C3 as well as fix
related compile errors

Also enables building of C3 test apps

components/mbedtls/test/test_mbedtls_sha.c

@@ -154,6 +154,7 @@ void tskRunSHASelftests(void *param)
             while (1) {}
         }
 
+#if SOC_SHA_SUPPORT_SHA512
         if (mbedtls_sha512_self_test(1)) {
             printf("SHA512 self-tests failed.\n");
             while (1) {}
@@ -163,6 +164,7 @@ void tskRunSHASelftests(void *param)
             printf("SHA512 self-tests failed.\n");
             while (1) {}
         }
+#endif //SOC_SHA_SUPPORT_SHA512
     }
     xSemaphoreGive(done_sem);
     vTaskDelete(NULL);