Build: Remove toolchain reset mechanism

The preload.cmake and compiler/linker reset magic is not necessary in
the split build. Building S and NS sides seprartely allows setting
configuration for setting CPU and Arch explicitly.

The changes applied for an521 platforms. Builds for regression tests.

Signed-off-by: Anton Komlev <anton.komlev@arm.com>
Signed-off-by: Dávid Házi <david.hazi@arm.com>
Change-Id: I4a431eab8a3cb13af2267290805d396285f57385
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5acf894..56ce8b8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -41,10 +41,11 @@
 ############################### Compiler configuration #########################
 
 include(${TFM_TOOLCHAIN_FILE})
-set(CMAKE_PROJECT_INCLUDE_BEFORE ${CMAKE_SOURCE_DIR}/cmake/disable_compiler_detection.cmake)
+
+set(CMAKE_C_COMPILER_FORCED true)
+set(CMAKE_CXX_COMPILER_FORCED true)
 
 project("Trusted Firmware M" VERSION ${TFM_VERSION} LANGUAGES C CXX ASM)
-tfm_toolchain_reload_compiler()
 
 add_subdirectory(lib/ext)
 add_subdirectory(lib/fih)