Instead of having users of the ChromeOS EC call the interface-specific
cmd_xfer() callback directly, introduce a central cros_ec_cmd_xfer()
to use instead.  This will allow us to put all the locking and retry
logic in one place instead of duplicating it across the different
drivers.
Signed-off-by: NAndrew Bresticker <abrestic@chromium.org>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>