ASoC: Intel: bytcr_rt5651: Fix DMIC map headsetmic mapping

The initial bytcr_rt5651 machine driver commit mapped IN2 as the headset
mic. In retrospect this is not correct as all known boards have the headset
mic on IN3.

This commit fixes the original DMIC mapping to correctly have the headset
mic on IN3.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>