asoc: add multi stream support for display port

Add support to share a common display afe port between
two pcm streams.
Add mixer controls to set/get format, channels, sample rate
and configure controller/stream for display port 1.

Change-Id: Ie8fb95d57fba129e623c7513ec92dd800b5ea80b
Signed-off-by: Vignesh Kulothungan <vigneshk@codeaurora.org>