stout: use 0x6c/0x68 to avoid racing with kernel ACPI driver

This uses a sideband port with a slightly modified command set for
reading EC RAM data.

BRANCH=stout
BUG=chrome-os-partner:14480
TEST=tested on stout

Change-Id: Ic5908e6240b044d5901a26ce61b9393d0b6daa04
Reviewed-on: https://gerrit.chromium.org/gerrit/36039
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Commit-Ready: David Hendricks <dhendrix@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/36985
1 file changed