Interface: Improvements on framework_feature

- Restrict variable replacement on "@VAR@" only
- Set PSA_FRAMEWORK_ISOLATION_LEVEL before configure_file
- Add invalid config check on:
    TFM_LIB_MODEL AND PSA_FRAMEWORK_ISOLATION_LEVEL

Change-Id: Ib3a681716dfb148f62ca4ea0c03b2de9a65b7ca5
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
diff --git a/interface/CMakeLists.txt b/interface/CMakeLists.txt
index bc216b8..ec7f2d1 100644
--- a/interface/CMakeLists.txt
+++ b/interface/CMakeLists.txt
@@ -10,8 +10,10 @@
 cmake_policy(SET CMP0079 NEW)
 
 # Generate framework feature
+set(PSA_FRAMEWORK_ISOLATION_LEVEL   ${TFM_ISOLATION_LEVEL})
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/include/psa/framework_feature.h.in
-               ${CMAKE_BINARY_DIR}/generated/interface/include/psa/framework_feature.h)
+               ${CMAKE_BINARY_DIR}/generated/interface/include/psa/framework_feature.h
+               @ONLY)
 
 if (TFM_MULTI_CORE_TOPOLOGY)
     include(${CMAKE_SOURCE_DIR}/platform/ext/target/${TFM_PLATFORM}/preload_ns.cmake)