greybus: interface: hibernate UniPro link in activation error path

To be well-behaved, we should hibernate the link before disabling UniPro
in case the link has already been established (i.e. when the interface
type has been detected as UniPro or Greybus).

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Sandeep Patil <sspatil@google.com>
Reviewed-by: Patrick Titiano <ptitiano@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>