ukify: Support building UKIs with .dtbauto and .hwids sections (#34158)

Stub behavior will be as following:
1. If there are no `.dtbauto` sections then is used `.dtb` if present
2. If there are `.dtbauto` sections and there is at least one matching
(either with the firmware-provided DT or via `.hwids`) then it'll be
used instead of the `.dtb`.

Based on #28959 and [dtbloader](https://github.com/TravMurav/dtbloader)

Closes #28959
Fixes #31946