[M] Change in coreboot[master]: mb/google/myst: Enable PCIe devices in devicetree

[Jon Murphy (Code Review)]

Attention is currently required from: Raul Rangel, Tim Van Patten, Karthik Ramasubramanian, Mark Hasemeyer.

Jon Murphy has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74112 )

Change subject: mb/google/myst: Enable PCIe devices in devicetree
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Patch Set 31:

(1 comment)

File src/mainboard/google/myst/port_descriptors.c:

https://review.coreboot.org/c/coreboot/+/74112/comment/8baad13c_fba5c1b5 
PS31, Line 101: 	*dxio_descs = myst_phx_dxio_descriptors;
              : 	*dxio_num = ARRAY_SIZE(myst_phx_dxio_descriptors);
              : 	*ddi_descs = myst_phx_ddi_descriptors;
              : 	*ddi_num = ARRAY_SIZE(myst_phx_ddi_descriptors);
> Are these values actually specific to Phoenix? […]

I would expect them to keep working, but I think it's possible that there would be a delta.  We could probably just make it myst and update as needed