From: Andi Kleen <ak@suse.de>

We still need some kind of early CPU detection, e.g.  for the AMD768
workaround and for the slab allocator to size its slabs correctly for the
cache line.  Also some other code already had private early CPU routines.

This patch takes a new approach compared to the previous patch which caused
Andrew so much grief.  It only fills in a few selected fields in
boot_cpu_data (only the data needed to identify the CPU type and the cache
alignment).  In particular the feature masks are not filled in, and the
other fields are also not touched to prevent unwanted side effects.

Also convert the ppro workaround to use standard cpu data now. 

I'm not sure if slab still has the necessary support to use the cache line
size early; previously Manfred showed some serious memory saving with this
for kernels that are compiled for a bigger cache line size than the CPU (is
often the case on distribution kernels).  This code could be reenable now
with this patch.