ALSA: hda - Add stereo mic quirk for Lenovo G50-70 (17aa:3978)

commit bbba6f9d3da357bbabc6fda81e99ff5584500e76 upstream.

Lenovo G50-70 (17aa:3978) with Conexant codec chip requires the
similar workaround for the inverted stereo dmic like other Lenovo
models.

Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1020657


Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>