Change in coreboot[master]: soc/intel/{common,skl}: set ACPI_FADT_PLATFORM_CLOCK based on Kconfig

[Nico Huber (Code Review)]

Attention is currently required from:  Felix Singer, Furquan Shaikh, Mariusz Szafrański, Paul Menzel, Subrata Banik, Angel Pons, Michael Niewöhner, Patrick Rudolph, Lance Zhao, Tim Wawrzynczak, Suresh Bellampalli, Vanessa Eusebio, Michal Motyl.
Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/57934 )

Change subject: soc/intel/{common,skl}: set ACPI_FADT_PLATFORM_CLOCK based on Kconfig
......................................................................

Patch Set 22: Code-Review+2

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/57934/comment/895f557a_6d802f6f 
PS21, Line 14: 
Please mention the platforms that change behavior, e.g. APL/GLK
because for those USE_PM_ACPI_TIMER will always be false. Maybe
even the boards that default to !USE_PM_ACPI_TIMER.

DNV does not change afaics, as its soc_fill_fadt() overwrites
what acpi_fill_fadt() does, I guess.

Do we know the situation on Xeon-SP? If it doesn't select
PM_ACPI_TIMER_OPTIONAL, it will change behavior too.