This patch moves the suspend/resume mechanisms down to each codec
driver level, as we have a proper codec driver bound on the bus now.
Then we get the asynchronous PM gratis without fiddling much in the
driver level.

As a soft-landing transition, implement the common suspend/resume pm
ops for hda_codec_driver and keep the each codec driver intact.  Only
the callers of suspend/resume in the controller side (azx_suspend()
and azx_resume()) are removed.

Another involved place is azx_bus_reset() calling the temporary
suspend and resume as a hackish method of bus reset.  The HD-audio
core provide a helper function snd_hda_bus_reset() instead.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Now we create the standard HD-audio bus (/sys/bus/hdaudio), and bind
the codec driver with the codec device over there.  This is the first
step of the whole transition so that the changes to each codec driver
are kept as minimal as possible.

Each codec driver needs to register hda_codec_driver struct containing
the currently existing preset via the new helper macro
module_hda_codec_driver().  The old hda_codec_preset_list is replaced
with this infrastructure.  The generic parsers (for HDMI and other)
are also included in the preset with the special IDs to bind
uniquely.

In HD-audio core side, the device binding code is split to
hda_bind.c.  It provides the snd_hda_bus_type implementation to match
the codec driver with the given codec vendor ID.  It also manages the
module auto-loading by itself like before: when the matching isn't
found, it tries to probe the corresponding codec modules, and finally
falls back to the generic drivers.  (The special ID mentioned above is
set at this stage.)

The only visible change to outside is that the hdaudio sysfs entry now
appears in /sys/bus/devices, not as a sound class device.

More works to move the suspend/resume and remove ops will be
(hopefully) done in later patches.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>