The DSI driver is currently unaware of how the DSI physical data lanes
are mapped to the logical lanes provided by the DSI controller.

Create a DT binding "qcom,data-lane-map" that provides this information
on a given platform.

The MSM DSI controller is restricted in terms of what all mappings
it can support. The lane polarity is fixed for all the lanes, the clock
lanes are fixed, and the data lanes can be swapped among each other only
for a few combinations. Apply these restrictions when we parse the DT
data.

Cc: devicetree@vger.kernel.org
Cc: Rob Herring <robh@kernel.org>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>