dt-bindings: display: tfp410: Add bus parameters properties

The TFP410 supports configuration of several input bus parameters
through either the I2C port or chip pins. In the latter case, we need to
specify those parameters in DT.

Two new properties are added, ti,deskew to specify the data de-skew
configuration (as set through the DK[3:1] pins), and pclk-sample to
specify the pixel clock sampling edge (as set through the EDGE pin).

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>