Remove unnecessary include directory from CMake

Since psa_crypto.c does not include tests/include/test/memory.h, we do
not need the tests/include include path.

Signed-off-by: David Horstmann <david.horstmann@arm.com>

library/CMakeLists.txt

@@ -228,8 +228,7 @@ foreach(target IN LISTS target_libraries)
         PRIVATE ${MBEDTLS_DIR}/library/
         PRIVATE ${thirdparty_inc}
         # Needed to include psa_crypto_driver_wrappers.h
-        ${CMAKE_CURRENT_BINARY_DIR}
-        ${MBEDTLS_DIR}/tests/include/)
+        ${CMAKE_CURRENT_BINARY_DIR})
     target_compile_definitions(${target}
         PRIVATE ${thirdparty_def})
     # Pass-through MBEDTLS_CONFIG_FILE and MBEDTLS_USER_CONFIG_FILE