tools script: fix up mdk460 link error

tools/building.py

@@ -48,6 +48,7 @@ def PrepareBuilding(env, root_directory, has_libcpu=False, remove_components = [
         if not os.path.isfile(os.path.join(rtconfig.EXEC_PATH, 'armcc.exe')):
             if rtconfig.EXEC_PATH.find('bin40') > 0:
                 rtconfig.EXEC_PATH = rtconfig.EXEC_PATH.replace('bin40', 'armcc/bin')
+                Env['LINKFLAGS']=Env['LINKFLAGS'].replace('RV31', 'armcc')
 
     # patch for win32 spawn
     if env['PLATFORM'] == 'win32' and rtconfig.PLATFORM == 'gcc':