fbdev: sh_mipi_dsi: use platform provided register layout and values

Different sh-mobile SoCs have variations in their MIPI DSI register layouts,
besides, different LCD panels require different configuration parameters. This
patch switches the driver to use platform-provided MIPI DSI parameters.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>