intel_sst: DMIC routing

This patch adds support for configuring and routing the
DMICs (assigned HW route to DMICs)

Signed-off-by: Sitanshu Nanavati <sitanshu.nanavati@intel.com>
Signed-off-by: Ramesh Babu K V <ramesh.babu@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>