kona: move display port mixers to common block

Move Display Port mixer controls to common mixer control array,
so that those can be exercised for Kona sound card with Bolero/Traverso
codecs.

Change-Id: I4f27694b554fc9f1e2070fdf3056b3c8f71d57d3
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>