ALSA: jack: implement kctl creating for jack devices

Currently the ALSA jack core registers only input devices for each jack
registered. These jack input devices are not readable by userspace devices
that run as non root. This patch series will implement kctls inside the
core jack part, including kctls creating, status changing report, for both
HD-Audio and ASoC jack. This allows non root userspace to read jack status
and act on it.

This patch adds a new API called snd_jack_add_new_kctl(), which will create
a kcontrol, add it to the card, and also attach it to the jack kctl list.

This patch also initialises the jack kctl list after jack is newed, and
reports kctl status when jack insertion/removal events occur.

snd_jack_new() is updated in the following patches to also support creating
phantom jacks and jack kcontrols. We then remove these duplicated features
from HDA jack and have jack kctls handled by core throughout HDA and ASoC.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Modified-by: Jie Yang <yang.jie@intel.com>
Signed-off-by: Jie Yang <yang.jie@intel.com>
Reveiwed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>