spd: Support 2667 MT/s DRAM speed

BUG=b:127609572
TEST=Read meminfo on a hatch where the 2667 MT/s DRAM is used

Change-Id: I9732003ec29ce43952cfe907645656564e48e15f
Reviewed-on: https://chromium-review.googlesource.com/1574869
Commit-Ready: Philip Chen <philipchen@chromium.org>
Tested-by: Philip Chen <philipchen@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
2 files changed