[XS] Change in coreboot[main]: mb/google/brox: Disable package c state demotion

[Shelley Chen (Code Review)]

Shelley Chen has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/79855?usp=email )

Change subject: mb/google/brox: Disable package c state demotion
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mb/google/brox: Disable package c state demotion

This needs to be disabled for RPL otherwise we'll hit the assertion:

[EMERG]  ASSERTION ERROR: file 'src/soc/intel/alderlake/fsp_params.c', line 1066

BUG=b:311450057,b:300690448
BRANCH=None
TEST=Tested that we didn't hit this assertion on the device after this
     change

Change-Id: Ib7b2484de2d84c980550fd951f1e30efab0ee197
Signed-off-by: Shelley Chen 
---
M src/mainboard/google/brox/variants/baseboard/brox/devicetree.cb
1 file changed, 4 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/55/79855/1

diff --git a/src/mainboard/google/brox/variants/baseboard/brox/devicetree.cb b/src/mainboard/google/brox/variants/baseboard/brox/devicetree.cb
index 23db754..552164a 100644
--- a/src/mainboard/google/brox/variants/baseboard/brox/devicetree.cb
+++ b/src/mainboard/google/brox/variants/baseboard/brox/devicetree.cb
@@ -14,6 +14,10 @@
    # S0ix enable
    register "s0ix_enable" = "1"

+	# Disable package C state demotion on Raptorlake as a W/A for S0ix issues
+	# seen on J0 and Q0 SKUs
+	register "disable_package_c_state_demotion" = "1"
+
    # DPTF enable
    register "dptf_enable" = "1"