ALSA: ad1889: Allocate resources with device-managed APIs

This patch converts the resource management in PCI ad1889 driver with
devres as a clean up.  Each manual resource management is converted
with the corresponding devres helper, and the card object release is
managed now via card->private_free instead of a lowlevel snd_device.
Also, the unnecessary ac97 free callbacks are removed, too.

This should give no user-visible functional changes.

Link: https://lore.kernel.org/r/20210715075941.23332-9-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>