platform/chrome: Add Chrome OS EC userspace device interface

This patch adds a device interface to access the
Chrome OS Embedded Controller from user-space.

Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-by: Simon Glass <sjg@google.com>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

diff --cc Documentation/ioctl/ioctl-number.txt
Simple merge

diff --cc drivers/platform/chrome/Kconfig
Simple merge

diff --cc drivers/platform/chrome/Makefile
Simple merge

diff --cc drivers/platform/chrome/cros_ec_dev.c
Simple merge

diff --cc drivers/platform/chrome/cros_ec_dev.h
Simple merge