Patch merged into coreboot/master: 703aa97 x86: harden tsc udelay() function

the following patch was just integrated into master:
commit 703aa978aa6db915fbc7fa42e5ca79cf31f57505
Author: Aaron Durbin 
Date:   Wed May 1 15:55:14 2013 -0500

x86: harden tsc udelay() function

Since the TSC udelay() function can be used in SMM that means the
    TSC can count up to whatever value. The current loop was not handling
    TSC rollover properly. In most cases this should not matter as the TSC
    typically starts ticking at value 0, and it would take a very long time
    to roll it over. However, it is my understanding that this behavior is
    not guaranteed. Theoretically the TSC could start or be be written to
    with a large value that would cause the rollover.

Change-Id: I2f11a5bc4f27d5543e74f8224811fa91e4a55484
    Signed-off-by: Aaron Durbin 
    Reviewed-on: http://review.coreboot.org/3171
    Reviewed-by: Stefan Reinauer 
    Tested-by: build bot (Jenkins)
    Reviewed-by: Paul Menzel

Build-Tested: build bot (Jenkins) at Tue May  7 22:25:15 2013, giving +1
Reviewed-By: Stefan Reinauer  at Tue May  7 20:02:01 2013, giving +2
See http://review.coreboot.org/3171 for details.

-gerrit