[coreboot-gerrit] Change in coreboot[master]: drivers/intel/fsp2_0: factor out and improve UPD signature check

[Furquan Shaikh (Code Review)]

Attention is currently required from: Justin Frodsham, Raul Rangel, Subrata Banik, Andrey Petrov, Patrick Rudolph, Felix Held.
Furquan Shaikh has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/50090 )

Change subject: drivers/intel/fsp2_0: factor out and improve UPD signature check
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Patch Set 2: Code-Review+2

(1 comment)

File src/drivers/intel/fsp2_0/include/fsp/util.h:

https://review.coreboot.org/c/coreboot/+/50090/comment/d35b35fc_40cd379a 
PS2, Line 100: fsp_verify_upd_header_signature
nit: Add a comment that the function dies if signatures don't match?