cmake: Move platform specific parts to platform dir

Rename Config*.cmake files to reflect the target they build for.
Add target specific configuration options to CMake files, and set the
proper values in the  Config*.cmake files.
Eliminate direct inclusion of cmsis core_cm33.h
Update build instructions

Change-Id: I7f506b45e649ce3a0d31cc5784c6a01e1710935c
Signed-off-by: Mate Toth-Pal <mate.toth-pal@arm.com>
diff --git a/cmake/Common/FindArmClang.cmake b/cmake/Common/FindArmClang.cmake
index 7e02f51..08d743e 100644
--- a/cmake/Common/FindArmClang.cmake
+++ b/cmake/Common/FindArmClang.cmake
@@ -111,3 +111,6 @@
 
 STRING(REGEX REPLACE "([0-9]+)\.([0-9]+)(\.[0-9]+)*.*" "CompilerArmClang\\1\\2" ARMCLANG_MODULE "${ARMCLANG_VER}")
 
+if(NOT EXISTS "${CMAKE_CURRENT_LIST_DIR}/${ARMCLANG_MODULE}.cmake")
+	message(FATAL_ERROR "ERROR: Unsupported ARMCLANG compiler version found on PATH.")
+endif()