[GuestLoader]: Added autoboot for guestloader.

guestloader's squeance diagram : http://keslproject.iptime.org/mediawiki/images/0/05/Guestloader.jpg

1. Added CLI (command.*)
2. Added autoboot (main.c)
3. Fixed guestloader's memory map(Add sp for system/user mode)
4. Added writel/readl function in asm_io.h
5. Refactoring code.
6. Remove common/guest/command directory

CLI is worked on RTSM. Arndale is not supproted.