Add regression 1022 to test dlopen()/dlsym()/dlclose()

Adds a new test case for the dynamic link API in libdl.
- A new shared library is added in ta/os_test_lib_dl.
- In xtest 1022, the dl API is used to load the test library and
  retrieve pointers to functions.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
diff --git a/ta/os_test/include/os_test.h b/ta/os_test/include/os_test.h
index 57f8470..708d80f 100644
--- a/ta/os_test/include/os_test.h
+++ b/ta/os_test/include/os_test.h
@@ -44,5 +44,7 @@
 TEE_Result ta_entry_params(uint32_t param_types, TEE_Param params[4]);
 TEE_Result ta_entry_call_lib(uint32_t param_types, TEE_Param params[4]);
 TEE_Result ta_entry_call_lib_panic(uint32_t param_types, TEE_Param params[4]);
+TEE_Result ta_entry_call_lib_dl(uint32_t param_types, TEE_Param params[4]);
+TEE_Result ta_entry_call_lib_dl_panic(uint32_t param_types, TEE_Param params[4]);
 
 #endif /*OS_TEST_H */