[GuestLoader]: Added autoboot for guestloader.
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.