Splits x86 arch for circular deps

Apic.h will need to include atomic.h, which needs arch (for irqs), which was also housing the coreid code that needs the LAPIC.  Hence the split.

Signed off and written by Barret  =)
Well, it *almost* builds. What happened to core_id?

Signed-off-by: Ronald G. Minnich <rminnich@google.com>
This builds and boots.

if you ls '#a' you can see it parses ACPI.

Sorry for the huge code base churn. Our include files
really need some work however.

C compilers are fast now. I'd still push for just including
akaros.h and having it just include everything but that's me :-)

Signed-off-by: Ronald G. Minnich <rminnich@google.com>