[M] Change in coreboot[master]: soc/intel/xeon_sp/spr: Add soc_config_iio to set IIO UPD from mainboard

[Felix Singer (Code Review)]

Attention is currently required from: Angel Pons, Arthur Heymans, Christian Walter, Johnny Lin, Lean Sheng Tan, Naresh Solanki, Nill Ge, TangYiwei, Tim Chu, Ziang Wang.

Felix Singer has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/76185?usp=email )

Change subject: soc/intel/xeon_sp/spr: Add soc_config_iio to set IIO UPD from mainboard
......................................................................

Patch Set 5: Code-Review+1