[S] Change in coreboot[master]: mb/google/skyrim/var/winterhold: adjust the eDP panel power sequence

[Chris Wang (Code Review)]

Attention is currently required from: Jason Nien, Martin Roth.

Chris Wang has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/74759 )

Change subject: mb/google/skyrim/var/winterhold: adjust the eDP panel power sequence
......................................................................

mb/google/skyrim/var/winterhold: adjust the eDP panel power sequence

set pwr_down_bloff_to_varybloff to 0x2, which means fw will delay 8ms
between backlight off to vary blacklgiht off.

BUG=b:271704149
BRANCH=none
TEST=Build; Verify the UPD was passed to system integrated table.

Signed-off-by: Chris Wang 
Change-Id: Ifefd47a86e53d574098ae2e5bd2f41ae79353385
---
M src/mainboard/google/skyrim/variants/winterhold/overridetree.cb
1 file changed, 18 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/59/74759/1

diff --git a/src/mainboard/google/skyrim/variants/winterhold/overridetree.cb b/src/mainboard/google/skyrim/variants/winterhold/overridetree.cb
index 4297f90..1606f2b 100644
--- a/src/mainboard/google/skyrim/variants/winterhold/overridetree.cb
+++ b/src/mainboard/google/skyrim/variants/winterhold/overridetree.cb
@@ -114,6 +114,7 @@

# The unit is set to one per 4ms
    	register "pwr_on_vary_bl_to_blon" = "0x1c"
+		register "pwr_down_bloff_to_varybloff" = "0x2"

device ref gpp_bridge_1 on
    		# Required so the NVMe gets placed into D3 when entering S0i3.