Build: Alter operation of cmake preload files

Change-Id: I0659c171494ddece45435551fc0af43c7b880142
Signed-off-by: Raef Coles <raef.coles@arm.com>
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index c7aaf27..481ed1d 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -16,6 +16,7 @@
 # anything loaded from or declared in this dir.
 if (TFM_MULTI_CORE_TOPOLOGY)
     include(${CMAKE_SOURCE_DIR}/platform/ext/target/${TFM_PLATFORM}/preload_ns.cmake)
+    tfm_toolchain_reload_compiler()
 endif()
 
 add_subdirectory(test_services)