ASoC: simple-card-utils: create jack inputs for

Merge series from Astrid Rost <astrid.rost@axis.com>:

Add a generic way to create jack inputs for auxiliary jack detection
drivers (e.g. via i2c, spi), which are not part of any real codec.
The simple-card can be used as combining card driver to add the jacks,
no new one is required.

Create a jack (for input-events) for jack devices in the auxiliary
device list (aux_devs). A device which returns a valid value on
get_jack_type counts as jack device; set_jack is required
to add the jack to the device.