platform: Flatten platform folders.

Adding OEM name as one extra layer does not really help in finding right
platform, and is actually causing more problems before project is
officially launched; and that is why all modern projects always live in
"google" folder.

As a result, it seems more reasonable to just move every board into
platform/, which also makes it easier to maintain platform_list.c.

BRANCH=none
BUG=chromium:731016
TEST=emerge-eve mosys; mosys platform name

Change-Id: Ie473efadc2a3e336c969c645462dfbedb516cfd8
Reviewed-on: https://chromium-review.googlesource.com/575613
Commit-Ready: Hung-Te Lin <hungte@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@google.com>
268 files changed