[S] Change in coreboot[master]: mb/google/rex: Disable tbt_pcie_rp3 root port

[John Zhao (Code Review)]

John Zhao has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/68854 )

Change subject: mb/google/rex: Disable tbt_pcie_rp3 root port
......................................................................

mb/google/rex: Disable tbt_pcie_rp3 root port

Extra memory resource allocation is needed for bridge once a TBT PCIe
root port is enabled to support the hot plug feature. There is report
that touch screen device is not probed once all 4 ports are enabled.
This change disables the tbt_pcie_rp3(00:07.3) since it is not used.

BUG=b:254207628
TEST=Booted to OS and queried input device events via evtest. Verified
the touch screen ELAN6918 was shown up.

Change-Id: Ia5c1d657c0ad0482619d739f8949bc9168eac25b
Signed-off-by: zhaojohn 
---
M src/mainboard/google/rex/variants/rex0/overridetree.cb
1 file changed, 20 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/54/68854/1

diff --git a/src/mainboard/google/rex/variants/rex0/overridetree.cb b/src/mainboard/google/rex/variants/rex0/overridetree.cb
index 2e1c159..c13105a 100644
--- a/src/mainboard/google/rex/variants/rex0/overridetree.cb
+++ b/src/mainboard/google/rex/variants/rex0/overridetree.cb
@@ -138,7 +138,7 @@
    	device ref tbt_pcie_rp0 on end
    	device ref tbt_pcie_rp1 on end
    	device ref tbt_pcie_rp2 on end
-		device ref tbt_pcie_rp3 on end
+		device ref tbt_pcie_rp3 off end
    	device ref tcss_xhci on
    		chip drivers/usb/acpi
    			device ref tcss_root_hub on