Tools: Topology: Add channels downnmix to nocodec topologies

This patch adds to PCM0 playback pipeline the selector/micsel
component to allow playback of 1-8ch content with conversion
stereo.

There is no change to capture pipelines. The ASCII diagram for
SSP0 is only update to show the current pipelines with module
copiers and gain.

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

Author: singalsu