mosys: oak: get version from cros_ec

Since chromium:663243, the board version reported by mosys should be "revN"
for both x86 and non-x86 platforms. Few older platforms, for example nyan
and oak, were printing whole device tree identifier which is not the right
format, and cannot really identify board revision.

As a result we should fix that by using the version reported from EC.

BUG=None
TEST=emerge-elm mosys; emerge-kukui mosys; mosys platform version

Change-Id: I538e593e674e6b9d1261619c81f7f00c2fcee393
Reviewed-on: https://chromium-review.googlesource.com/1367205
Commit-Ready: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
1 file changed