root_thread adds mapping to hardware device memory
Merge pull request #88 from georgekang/master

memory: map hardware device regions in root_thread
added hello apps
use L4_Sleep() to replace delay loop of hello app
Merge remote-tracking branch 'origin/master' into myapps
Merge branch 'myapps' of https://github.com/KunYi/f9-kernel into myapps