greybus: define BUNDLE_ID_NONE

Define a bundle ID that means "no bundle".  This will be used for
tracing connection events during the portion of a connection's
lifetime when it has no bundle associated with it.  Don't allow
any bundle to be created using that ID.

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