ALSA: hda - Don't access stereo amps for mono channel widgets

ALSA: hda - Don't access stereo amps for mono channel widgets

The current HDA generic parser initializes / modifies the amp values
always in stereo, but this seems causing the problem on ALC3229 codec
that has a few mono channel widgets: namely, these mono widgets react
to actions for both channels equally.

In the driver code, we do care the mono channel and create a control
only for the left channel (as defined in HD-audio spec) for such a
node.  When the control is updated, only the left channel value is
changed.  However, in the resume, the right channel value is also
restored from the initial value we took as stereo, and this overwrites
the left channel value.  This ends up being the silent output as the
right channel has been never touched and remains muted.

This patch covers the places where unconditional stereo amp accesses
are done and converts to the conditional accesses.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=94581
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>