regression: add tests for the supplicant plugin framework

Add test cases for checking functionality of supplicant plugins:
 - Ability to pass values and arrays to/from a plugin
 - Right handle situations with bad input parameters
 - Right handle situations with calling an unknown plugin

Signed-off-by: Aleksandr Anisimov <a.anisimov@omprussia.ru>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
diff --git a/host/xtest/xtest_test.h b/host/xtest/xtest_test.h
index aed4ca0..892c7f7 100644
--- a/host/xtest/xtest_test.h
+++ b/host/xtest/xtest_test.h
@@ -133,6 +133,7 @@
 extern const TEEC_UUID socket_ta_uuid;
 extern const TEEC_UUID sdp_basic_ta_uuid;
 extern const TEEC_UUID tpm_log_test_ta_uuid;
+extern const TEEC_UUID supp_plugin_test_ta_uuid;
 extern char *xtest_tee_name;
 
 #endif /*XTEST_TEST_H*/