greybus: audio: Remove unnecessary num_jack field from module_info

snd_jack will be registered based on real capabilities shared by
module's FW instead of parsing widgets and register it with fixed
capabilities. Remove module_info->num_jack, since it is no more
required.

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>