ASoC: Intel: Atom: Configure media_loop1 and sprot_loop in stereo

Most of the devices are using stereo speakers so media_loop1 and
sprot_loop default mode should be stereo.

As per default all the routing UCM configuration doesn't enable Post
processing loops it is not impacting curent configurations.

Signed-off-by: Sebastien Guiriec <sebastien.guiriec@intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>