Patch merged into coreboot/master: x86/smm: Initialize SMM on some CPUs one-by-one

the following patch was just integrated into master:
commit 149c4c5d0191f1728a66ec986c3eae698cbf87cb
Author: Damien Zammit 
Date:   Sat Nov 28 21:27:05 2015 +1100

x86/smm: Initialize SMM on some CPUs one-by-one

We currently race in SMM init on Atom 230 (and potentially
    other CPUs). At least on the 230, this leads to a hang on
    RSM, likely because both hyperthreads mess around with
    SMBASE and other SMM state variables in parallel without
    coordination. The same behaviour occurs with Atom D5xx.

Change it so first APs are spun up and sent to sleep, then
    BSP initializes SMM, then every CPU, one after another.

Only do this when SERIALIZE_SMM_INITIALIZATION is set.
    Set the flag for Atom CPUs.

Change-Id: I1ae864e37546298ea222e81349c27cf774ed251f
    Signed-off-by: Patrick Georgi 
    Signed-off-by: Damien Zammit 
    Reviewed-on: https://review.coreboot.org/6311
    Tested-by: build bot (Jenkins)
    Tested-by: BSI firmware lab 
    Reviewed-by: Aaron Durbin

See https://review.coreboot.org/6311 for details.

-gerrit