drivers: display_sdl: rework to obtain configuration from devicetree

Add bindings for SDL based display controller.
Rework SDL based display controller driver to obtain
configuration from devicetree. Remove unnecessary casts,
add multi-instance support.

Add display controller node and chosen property
to native_posix devicetree.

Signed-off-by: Johann Fischer <johann.fischer@nordicsemi.no>
3 files changed