Make use of Rusty's early_param code. Its good stuff.

We appear to be the first user :)

Move vpa_init and idle_setup later in boot, we dont have to do them
right up front in setup_system.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>