nb/intel/sandybridge: Fix PEG disablement

Fix regression introduced by:
3660c0fc658e4e20ef079f762dfc7ad05c83544c
"northbridge/intel/sandybridge: Enable PEG clock-gating on demand"

Issue observed:
GNU/Linux kernel crashes in earlyinit on systems without PEG devices.
The crash occurs on every boot in different functions.
There's no problem on systems with PEG enabled.

Test system:
 * Lenovo T530
 * Intel Core i5-3320M CPU
 * Fedora GNU/Linux 4.1
 * PEG disabled in devicetree

Problem description:
Tests shows that modifing PEG chicken bit or device enable bits
after setting BIOS_RESET_CPL causes random crashes in GNU/Linux.

Problem solution:
Disable PEG devices before setting BIOS_RESET_CPL.

Final testing results:
No more random kernel crashes.

Change-Id: I4a967c2d00d7d1e4426cf5abdd5f616c21557da7
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: http://review.coreboot.org/12112
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>

0 files changed, 0 insertions, 0 deletions