We're going to support sku-id as an unibuild identifier for ARM:

https://chromium-review.googlesource.com/c/chromiumos/platform/mosys/+/1274767

https://chromium-review.googlesource.com/c/chromiumos/platform2/+/1271458


As both x86 and ARM share sku-id identity, we should be able to better consolidate the ways we identify boards/models in unibuild.

Please find more details in Charles' comments here:

When these (x86 vs arm) were method level deltas, i guess it didn't matter as much, but now it stands out a bit more

for x86, we read smbios and then call this method
for arm, we call this method and let it read device compatible string 

it's inconsistent and causes a lot of the ifdefs

could we change it to:
x86 - read smbios
arm - read dt compatible string

normalize this to platform name match (we could also collapse the yaml also now since they share sku)

now we'd share all of the cros_config match code and just have the deltas on the identity read (which is the only part that's actually different)