ASoC: wcd9335: Add support to connect codec dai to mixing path

Currently AIFn_PB codec dai's are allowed to connect only to
primary path. Add support to connect them to codec mixing path
so as to support audio concurrencies.

Change-Id: Id9d3c32c498abc4720836dad305113afaa13559f
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>