intel/skylake: Adding provision to set voltages to the I2C ports

intel/skylake: Adding provision to set voltages to the I2C ports

This patch adds an UPD/VPD parameter to set voltages to the
I2C ports individually via devicetree.cb

BRANCH=None
BUG=chrome-os-partner:47821
TEST=Tesed by setting voltage via devicetree.cb
and verified voltage level using a DSO probe.

CQ-DEPEND=CL:*242225, CL:*241206

Change-Id: Iaeb1ab3f9724aa1139c876dc63250469661d8439
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: fc73b98529ad1eb187f97a4177beda4224f473d1
Original-Change-Id: Ib477ad26667ef59cd298b5e20a68a8c68d85bd8d
Original-Signed-off-by: Naresh G Solanki <Naresh.Solanki@intel.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/315167
Original-Commit-Ready: Naresh Solanki <naresh.solanki@intel.com>
Original-Tested-by: Naresh Solanki <naresh.solanki@intel.com>
Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://review.coreboot.org/13006
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>