[PATCH] x86: hot plug CPU to support physical add of new processors

The patch allows physical bring-up of new processors (not initially present
in the configuration) from facilities such as driver/utility implemented on
a platform.  The actual method of making processors available is up to the
platform implementation.

Signed-off-by: Natalie Protasevich <Natalie.Protasevich@unisys.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Zwane Mwaikambo <zwane@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>