[S] Change in coreboot[master]: mb/google/skyrim: Enable UPD usb3_port_force_gen1 for Markarth

[John Su (Code Review)]

Attention is currently required from: Jason Nien, Chris Wang, Martin Roth, Patrick Huang, Karthik Ramasubramanian.

John Su has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74087 )

Change subject: mb/google/skyrim: Enable UPD usb3_port_force_gen1 for Markarth
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Patch Set 2:

(1 comment)

File src/mainboard/google/skyrim/variants/markarth/overridetree.cb:

https://review.coreboot.org/c/coreboot/+/74087/comment/ab1e2938_b7bd5f48 
PS1, Line 15:
> just to confirm, Markarth will force all type-c to gen1,or all usb3.0 ports?  […]

From request, limit all type-C port to Gen1 on Markarth.
I was updated CL for this setting and also check to use "lsusb -t" on my DUT.