Change in coreboot[master]: drivers/intel/dptf: Add support for PCH methods

[Tim Wawrzynczak (Code Review)]

Attention is currently required from: Furquan Shaikh, Sumeet R Pawnikar, Patrick Rudolph, Karthik Ramasubramanian, Felix Held.
Tim Wawrzynczak has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/57925 )

Change subject: drivers/intel/dptf: Add support for PCH methods
......................................................................

Patch Set 7: Code-Review+1

(2 comments)

File src/drivers/intel/dptf/dptf.c:

https://review.coreboot.org/c/coreboot/+/57925/comment/dfb34352_a055c2f2 
PS7, Line 230: acpigen_write_package(1);
             : 	acpigen_write_zero();
Since this is unrelated to this change, could this be separate commit? Also please update the comment to explain what the returned value is used for

https://review.coreboot.org/c/coreboot/+/57925/comment/6f1b2171_64d6a32d 
PS7, Line 292: "\_SB_.DPTF.TPCH.PKGC"
I think just 
`"PKGC"`
should work here because it's in the same scope