On Minnowboard Max with Realtek rt5651 eval board, the IN3P is
connected to Headset Mic.

Here add and select it for Minnowboard Max.
Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>