Change in coreboot[master]: [WIP] soc/intel/common: Add InSMM.STS support

[Angel Pons (Code Review)]

Attention is currently required from: Nico Huber, Benjamin Doron, Paul Menzel, Patrick Rudolph.
Hello build bot (Jenkins), Michael Niewöhner, Patrick Rudolph,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/51796

to look at the new patch set (#8).

Change subject: [WIP] soc/intel/common: Add InSMM.STS support
......................................................................

[WIP] soc/intel/common: Add InSMM.STS support

Tested on HP 280 G2, SMMSTORE (v1) still works.

Other tests:
- If one does not set BIOS_CONTROL bit WPD, SMMSTORE breaks.
- If one does not write the magic MSR `or 1`, SMMSTORE breaks.

Change-Id: Ia90c0e3f8ccf895bfb6d46ffe26750393dab95fb
Signed-off-by: Angel Pons 
---
M src/soc/intel/common/block/smm/smihandler.c
M src/soc/intel/common/pch/lockdown/lockdown.c
2 files changed, 27 insertions(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/96/51796/8