Change in coreboot[master]: src/drivers/intel/fsp2_0: allow larger FSP 2.0 header

[Subrata Banik (Code Review)]

Attention is currently required from: Michał Żygowski, Furquan Shaikh, Marshall Dawson, Nikolai Vyssotski, Andrey Petrov, Patrick Rudolph, Nathaniel L Desimone.
Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/56190 )

Change subject: src/drivers/intel/fsp2_0: allow larger FSP 2.0 header
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Patch Set 3:

(1 comment)

File src/drivers/intel/fsp2_0/util.c:

https://review.coreboot.org/c/coreboot/+/56190/comment/53ec4c0f_aa171cb7 
PS3, Line 14: looks_like_fsp_header
can we change this code like below?

1. Read FSP_INFO_HEADER.SpecVersion
2. If (FSP_INFO_HEADER.SpecVersion == 0x20) // FSP 2.0 Header
  - Check if FSP_INFO_HEADER.HeaderLength is either 0x48 and 0x4C as you might have some platform where EDK2 latest version cause FSP header length appear as 0x4C rather 0x48 as per spec 2.0. Consider we accommodate the violation as well.
3. If (FSP_INFO_HEADER.SpecVersion == 0x22) // FSP 2.2 Header
  - Check if FSP_INFO_HEADER.HeaderLength is 0x4c
4. Else return false and print error ?