Revert "UPSTREAM: mb/google/volteer/variants/delbin: Disable PmcUsb2PhySusPgEnable"

This reverts commit 2631e58936362a080f15bd716a4b72c58523430e.

Reason for revert: the CL is not needed in this branch.

Original change's description:
> UPSTREAM: mb/google/volteer/variants/delbin: Disable PmcUsb2PhySusPgEnable
>
> eDP panel flicker during system idle state is observed.
> Disabling USB2 SUS well power gating can remove flicker symptom.
> Please refer to doc#634894 for more details.
>
> BUG=b:182323059
> BRANCH=None
> TEST=Boot and confirm no display flicker.
>
> Change-Id: I3c0b86acd4da80d9c93ada41b9bff1d0611c3bf3
> Signed-off-by: Patrick Georgi <pgeorgi@google.com>
> Original-Commit-Id: c6bc3a56d684307770737a0ca1c34690a1289d00
> Original-Signed-off-by: Ravi Sarawadi <ravishankar.sarawadi@intel.com>
> Original-Change-Id: Icadf9c494fab82b219317c3ca3b04f633b543083
> Original-Reviewed-on: https://review.coreboot.org/c/coreboot/+/51613
> Original-Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
> Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/coreboot/+/2781720
> Reviewed-by: Patrick Georgi <pgeorgi@chromium.org>
> Commit-Queue: Patrick Georgi <pgeorgi@chromium.org>
> Tested-by: Patrick Georgi <pgeorgi@chromium.org>
> (cherry picked from commit b3dce4a1e6793aa3d29302c427b20e757331c0da)
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/coreboot/+/2782410
> Reviewed-by: YH Lin <yueherngl@chromium.org>
> Commit-Queue: YH Lin <yueherngl@chromium.org>
> Tested-by: YH Lin <yueherngl@chromium.org>

Bug: b:182323059
Change-Id: I3f79c09f712222f957ebcd66d8269ba1c366aa5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/coreboot/+/2783370
Reviewed-by: YH Lin <yueherngl@chromium.org>
Commit-Queue: YH Lin <yueherngl@chromium.org>
Tested-by: YH Lin <yueherngl@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
diff --git a/src/mainboard/google/volteer/variants/delbin/overridetree.cb b/src/mainboard/google/volteer/variants/delbin/overridetree.cb
index c111731..5e9600b 100644
--- a/src/mainboard/google/volteer/variants/delbin/overridetree.cb
+++ b/src/mainboard/google/volteer/variants/delbin/overridetree.cb
@@ -2,8 +2,6 @@
 	register "DdiPort1Hpd" = "0"
 	register "DdiPort2Hpd" = "0"
 
-	register "usb2_phy_sus_pg_disable" = "1"
-
 	#+-------------------+---------------------------+
 	#| Field             |  Value                    |
 	#+-------------------+---------------------------+