mdss: display: add video display interface support

Video mode display interface is used by DSI, HDMI and EDP controllers.
Implement MDP support in order to setup data path to these controllers.

Change-Id: Ibc766a1d10a55bcf64a3ab693db034a378afe4ee
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>