[L] Change in coreboot[master]: mb/google/rex/var/screebo: Add initial devicetree config

[Kun Liu (Code Review)]

Attention is currently required from: Tarun Tuli, Kapil Porwal.

Kun Liu has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74972 )

Change subject: mb/google/rex/var/screebo: Add initial devicetree config
......................................................................

Patch Set 5:

(3 comments)

File src/mainboard/google/rex/variants/screebo/overridetree.cb:

https://review.coreboot.org/c/coreboot/+/74972/comment/d07dffeb_c326e1a8 
PS4, Line 6: 9
> `8`

Done

https://review.coreboot.org/c/coreboot/+/74972/comment/1e80f899_44504e25 
PS4, Line 12: OC_SKIP
> `OC1`

Done

https://review.coreboot.org/c/coreboot/+/74972/comment/387a4f92_64fa97a0 
PS4, Line 281: usb2_port3
> PLD for `usb2_port3` and `usb3_port2` should be same. […]

+----------------+
   |                |
   |     Screen     |
   |                |
   +----------------+
C1 |                | C0
   |                | A0
   |                | A1
   +----------------+