Keith Hui uploaded patch set #5 to this change.

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sb/intel/i82371eb: Implement SMBus Control Method Interface support

Upcoming ACPI support for asus/p3b-f mainboard contains ASL code to
manipulate its AS99127F chip over SMBus before and after suspend,
to blink front panel lights, turn off fans, among other things.
This code caused an ACPI/PCI resource conflict that disabled access to
the entire SMBus, rendering its hardware monitor inoperative, and all
resolution attempts so far have not worked.

This change grows the ASL SMBus routines into a complete enough SMBus
Control Method Interface (SCMI) implementation, that Linux kernel can
use via the i2c-scmi driver, sidestepping this conflict.

The new routines are in a separate file, with OpRegion aligned with
other Intel southbridges, so that it can be more widely adopted with
minimal edits.

This change is guarded by a user-selectable Kconfig option, but forced
enabled for asus/p3b-f. Reason is other i82371eb boards may benefit
from, but do not require this change.

Developed and tested on asus/p3b-f, where:
- Linux 5.4.42 autoloads i2c-scmi (4.4.14 cannot)
- dmesg shows no more conflict with i2c-piix4 blacklisted
- i2cdetect can find the 3 i2c addresses of AS991227F
- with w83781d module loaded, lm-sensors can get readings

Change-Id: I97deb2d292af25e42068474f48e11c94a7480be6
Signed-off-by: Keith Hui <buurin@gmail.com>
---
M src/southbridge/intel/i82371eb/Kconfig
M src/southbridge/intel/i82371eb/acpi/i82371eb.asl
A src/southbridge/intel/i82371eb/acpi/smbus.asl
3 files changed, 205 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/35/41735/5

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Gerrit-Project: coreboot
Gerrit-Branch: master
Gerrit-Change-Id: I97deb2d292af25e42068474f48e11c94a7480be6
Gerrit-Change-Number: 41735
Gerrit-PatchSet: 5
Gerrit-Owner: Keith Hui <buurin@gmail.com>
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