soc/intel/skylake: Enable LPC IO Decoding on PCR

According to the PCH BIOS Spec (Doc#549921/Rev-2.3.4),
section 2.5.1.6, it is a requirement to program the same
value programmed in LPC "PCI offset 82h" into "PCR[DMI]+2774h"
to fully enable the Lpc IO enable decoding which is missing in
current source.

Without above changes, Skylake Saddlebrook platform with a
SIO does not boot.

Change-Id: Ief26e2718325b9d74ea0f83d47d2f917e0972173
Signed-off-by: praveen <praveenx.hodagatta.pranesh@intel.com>
Reviewed-on: https://review.coreboot.org/22819
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
1 file changed