Extend the i.MX53 framebuffer to support overlays
Implement framebuffer, touchscreen, and buttons for i.MX53 tablet

* Make I2C and GPIO accessible for secure world only
* Fix caching issue by flushing VM state memory by hand
* Fix scheduling issue by handling non-secure world like the idle thread
* Add input driver containing touchscreen, and capacitative button events
* Modify framebuffer driver to support i.MX53 tablet inclusive overlay functionality
reorganize
Add VMM GUI
Use VMM GUI for Trustzone VMM, introduce Vm pause functionality
Beautify VMM GUI
Fix bug when initially switching to fullscreen when no VM is running