[M] Change in coreboot[main]: vendorcode/intel: allow selecting EDK headers manually

[Sergii Dmytruk (Code Review)]

Attention is currently required from: Martin L Roth, Ronak Kanabar.

Sergii Dmytruk has posted comments on this change by Sergii Dmytruk. ( https://review.coreboot.org/c/coreboot/+/83738?usp=email )

Change subject: vendorcode/intel: allow selecting EDK headers manually
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Patch Set 3:

(1 comment)

File src/vendorcode/intel/Kconfig:

https://review.coreboot.org/c/coreboot/+/83738/comment/df7f2e45_b5cc21bf?usp... :
PS3, Line 34: PAYLOAD_EDK2
> Just thinking here, so feel free to ignore this. […]

Are you proposing to reverse the dependency?  I.e. add something like this here (unless there is a more suitable file):
```
config UEFI_PAYLOAD
    def_bool n
    help
      Select this in a payload to indicate that it follows UEFI specification.
```
Use `UEFI_PAYLOAD` instead of `PAYLOAD_EDK2` in this file and update `payloads/external/edk2/Kconfig`:
```
config PAYLOAD_EDK2
    ...
    select  UEFI_PAYLOAD
    ...
```
Not sure there will be non-EDK2 UEFI payload, but this solution would be cleaner if I understood it correctly.