drm/msm/dsi: Use a standard DT binding for data lanes

A more standard DT binding describing data lanes already exists here:
Documentation/devicetree/bindings/media/video-interfaces.txt

Use this binding instead of "qcom,data-lane-map". One difference
in the standard binding w.r.t to the existing binding is that it
provides a logical to physical mapping instead of the other way
round. Tweak the code to translate the data the way we want it.

The MSM DSI DT bindings aren't used anywhere at the moment, so
it's okay to update this property.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>