dt-bindings: display: bridge: Document Freescale i.MX93 MIPI DSI

Freescale i.MX93 SoC embeds a Synopsys Designware MIPI DSI host
controller and a Synopsys Designware MIPI DPHY.  Some configurations
and extensions to them are controlled by i.MX93 media blk-ctrl.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230821034008.3876938-9-victor.liu@nxp.com