Added various builtin character devices

Added /dev/(null|mem|kmem|zero|full|random|urandom|port)
Port and the randoms need to be properly implemented.
Removed empty file
Moved tss.c to i386 directory
Removed old i386 entry point
Removed stupid kludge in uhci code
Commiting these two files ahead of a rewrite

Both these files are a mess and need to be cleaned and in some parts
rewritten. This commit is to save all previous work ahead of that clean
up.