Removed redudant sample_threadX project from Cortex A7 ports_module IAR example_build. (#312)

https://msazure.visualstudio.com/One/_workitems/edit/25784627

Author: yajunxiaMS

ports_module/cortex_a7/iar/example_build/azure_rtos.eww

@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <workspace>
-    <project>
-        <path>$WS_DIR$\sample_threadx.ewp</path>
-    </project>
     <project>
         <path>$WS_DIR$\sample_threadx_module.ewp</path>
     </project>