dt-bindings: display: Add bindings for Novatek NT35950

The nt35950 IC from Novatek is a Driver IC used to drive MIPI-DSI panels,
with Static RAM for content retention in command mode and also supports
video mode with VESA Frame Buffer Compression or Display Stream Compression
on single, or dual dsi port(s).
This DDIC is also capable of upscaling an input image to the panel's native
resolution, for example it can upscale a 1920x1080 input to 3840x2160 with
either bilinear interpolation or pixel duplication.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210901173127.998901-2-angelogioacchino.delregno@somainline.org