dt-bindings: display: panel: Add bindings for NEC NL8048HL11 panel

The NEC NL8048HL11 is a 10.4cm WVGA (800x480) panel with a 24-bit RGB
parallel data interface and an SPI control interface.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190813201101.30980-4-laurent.pinchart@ideasonboard.com