greybus: Add Component Authentication Protocol support

This patch adds Component Authentication Protocol support in greybus.
The purpose of the CAP protocol is to authenticate the Module hardware,
and it can only be used when it is present as part of the
firmware-management bundle, on a separate CPort.

Compile tested only.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Jun Li <li_jun@projectara.com>
Tested-by: Jun Li <li_jun@projectara.com>
Signed-off-by: Alex Elder <elder@linaro.org>