Chell: Enable eMMC HS400 mode

With CL317451 and CL317267, Hynix eMMC can run under HS400 mode.

BUG=chrome-os-partner:47647
TEST=run consective boot 100 times on Chell EVT Hynix SKU, and
MMC errors didn't happen.
BRANCH=none

Change-Id: I6bec88f5c2813131a693ddba5523a9d43b2ebd45
Signed-off-by: Ryan Lin <ryan.lin@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/319627
Commit-Ready: Duncan Laurie <dlaurie@chromium.org>
Tested-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
1 file changed