greybus: audio: Report jack events conditionally

Now jack & jack-buttons are registered to snd_jack framework based on
the capability shared by module's topology data. Thus, jack events
should be reported to above snd framework only in case corresponding
jack type is registered. This patch adds additional checks to avoid
reporting fake jack events.

Signed-off-by: Vaibhav Agarwal <vaibhav.agarwal@linaro.org>
Reviewed-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>