ALSA: hda - Fix digital mic on Acer Aspire 3830TG

Acer Aspire 3830TG with CX20588 codec has a digital built-in mic that
has the same problem like many others, the inverted signal in stereo.
Apply the same fixup to this machine, too.

Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>