dt-bindings: display: sync formats with simplefb.h

Sync all formats from simplefb.h into documentation.

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://lore.kernel.org/r/20211108183322.68192-1-david@ixit.cz


Signed-off-by: Rob Herring <robh@kernel.org>