mosys: initial kukui support

Might need to modify some code when unified build is done.

TEST=emerge-kukui mosys; mosys -vvv platform name
TEST=emerge-elm mosys; mosys platform [sub]; mosys memory spd [sub]
BUG=b:120467912

Change-Id: I7b5e4e6a575fc7907b620fada773a3d874f66cdf
Reviewed-on: https://chromium-review.googlesource.com/1362267
Commit-Ready: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
5 files changed