feat: organise guest code with libs for each peri

guest/console/console.h

guest/console/console_pv.c

guest/gfx/gfx.h

guest/gfx/gfx_phys.c

guest/gfx/gfx_pv.c

guest/guest_main.c

guest/timer/timer.h

guest/timer/timer_phys.c

guest/timer/timer_pv.c