greybus: manifest: Disallow reuse of control cport

We should be checking if any of the bundles contains a CPort with its id
set to the special value of '0', which is reserved for control CPort.

Discard the bundle in that case.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>