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/CMakeLists.txt b/CMakeLists.txt
index 4cc1f38..6b91f23 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -31,3 +31,4 @@
 
 add_subdirectory (ta)
 add_subdirectory (host/xtest)
+add_subdirectory (host/supp_plugin)