mainboard/google: add initial rambi mainboard support

BUG=chrome-os-partner:23121
BRANCH=None
TEST=None

Change-Id: I283415be326e2d92e1e1bf7866954f17a7266edb
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/171940
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
Reviewed-on: http://review.coreboot.org/4865
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
21 files changed