Change in coreboot[master]: soc/intel/skylake: Set "PEG?Enable" UPD directly

[Angel Pons (Code Review)]

Attention is currently required from:  Felix Singer, Nico Huber, Benjamin Doron, Patrick Rudolph.
Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/50045 )

Change subject: soc/intel/skylake: Set "PEG?Enable" UPD directly
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Patch Set 4:

(2 comments)

Patchset:

PS4: 
I'm still not convinced this patch can really improve much. What's the reason for this change?

File src/soc/intel/skylake/romstage/romstage.c:

https://review.coreboot.org/c/coreboot/+/50045/comment/d579fdb0_deed1fbb 
PS4, Line 174: 	if (dev && dev->enabled) {
Now this will leave FSP UPDs unprogrammed for disabled PEG RPs. If you want to avoid rewriting the UPD, you have to write the desired values in one statement, and actually remove the write in the if-block:

m_cfg->Peg0Enable = dev && dev->enabled ? 2 : 0;
 if (m_cfg->Peg0Enable) { ...

How many nanoseconds does this shave off the boot time, though?