Some old AD codecs don't like the independent HP handling, either it
contains a single DAC (AD1981) or it mandates the mixer routing
(AD1986A).  This patch removes the indep_hp flag for such codecs.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=68081
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>