ASoC: sst v2: Add sn95031 codec driver

This patch adds the sn95031 asoc codec driver. This driver currently
supports only playback.  Capture and jack detection to be added later

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Harsha Priya <priya.harsha@intel.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>