With the commit 1ba8f9d3 ("ALSA: hda: Add a power_save
blacklist"), we changed the default value of power_save option to -1
for processing the power-save blacklist.
Unfortunately, this seems breaking user-space applications that
actually read the power_save parameter value via sysfs and judge /
adjust the power-saving status.  They see the value -1 as if the
power-save is turned off, although the actual value is taken from
CONFIG_SND_HDA_POWER_SAVE_DEFAULT and it can be a positive.

So, overall, passing -1 there was no good idea.  Let's partially
revert it -- at least for power_save option default value is restored
again to CONFIG_SND_HDA_POWER_SAVE_DEFAULT.  Meanwhile, in this patch,
we keep the blacklist behavior and make is adjustable via the new
option, pm_blacklist.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199073
Fixes: 1ba8f9d3

 ("ALSA: hda: Add a power_save blacklist")
Acked-by: Hans de Goede <hdegoede@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>