nocturne: configure VR per Intel recommendation

These values are Intel recommended.
IccMax = 28A
DC and AC LL = 4mOhms
Pl2 = 18w

BUG=b:79666828
BRANCH=none
TEST=Enabled p-states with patch 
Change-Id:I82d1516998cc26b789faa5d4e897feb06dc06020 and then
"emerge-nocturne depthcharge coreboot chromeos-bootimage", flash spi
image onto nocturne, boot to kernel and verify device stays alive and
responsive for several minutes without locking up.

Change-Id: I4c67c6a095aecc158e529a6b393baf03ec358a3d
Signed-off-by: Pratik Prajapati <pratikkumar.v.prajapati@intel.com>
Reviewed-on: https://review.coreboot.org/27175
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1 file changed