[S] Change in coreboot[main]: util/cbfstool: Add Intel platform boot policy support

[Angel Pons (Code Review)]

Attention is currently required from: Alicja Michalska, Arthur Heymans, Chen, Gang C, Jincheng Li, Shuo Liu.

Angel Pons has posted comments on this change by Shuo Liu. ( https://review.coreboot.org/c/coreboot/+/84305?usp=email )

Change subject: util/cbfstool: Add Intel platform boot policy support
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Patch Set 1:

(4 comments)

File src/southbridge/intel/common/firmware/Kconfig:

PS1: 
`southbridge/intel/common/firmware/Kconfig` is about the IFD (Intel Flash Descriptor) and its regions. For FIT stuff, I believe the correct location for these settings would be somewhere in `cpu/intel/fit` instead.

https://review.coreboot.org/c/coreboot/+/84305/comment/83a3a817_36f4006a?usp... :
PS1, Line 27: config HAVE_PBP_BIN
            : 	bool "Add Intel platform boot policy file"
            : 	default n
Not all FIT-capable platforms support PBP. So this option needs to be guarded by another option that is selected by platforms or mainboards that support PBP:

```suggestion
config PLATFORM_SUPPORTS_PBP_IN_FIT
    def_bool n

config HAVE_PBP_BIN
    bool "Add Intel platform boot policy file"
    depends on PLATFORM_SUPPORTS_PBP_IN_FIT
    default n
```

https://review.coreboot.org/c/coreboot/+/84305/comment/94c43c08_9687059b?usp... :
PS1, Line 31: 	  The platform boot policy file
Looks like this sentence ends halfway through, is this intentional?

https://review.coreboot.org/c/coreboot/+/84305/comment/e39655d9_f647e7c8?usp... :
PS1, Line 35: 	default "3rdparty/blobs/mainboard/$(MAINBOARDDIR)/pbp.bin"
Can PBP blobs be published to the blobs repo? If not, I would suggest setting the default path to somewhere in `site-local`:

```suggestion
    default "site-local/mainboard/$(MAINBOARDDIR)/pbp.bin"
```