dt-bindings: msm/dsi: Use standard data lanes binding

The "qcom,data-lane-map" binding mentioned in the document is changed to
the more generic "data-lanes" property specified in:

Documentation/devicetree/bindings/media/video-interfaces.txt

The previous binding expressed physical to logical data lane mappings,
the standard "data-lanes" binding uses logical to physical data lane
mappings. Update the docs to reflect this change. The example had the
property incorrectly named as "lanes", update this too.

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

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