dt-bindings: display: add BOE 14" panel

Add bindings for the BOE NV140FHM-N49 14" 1920x1080 panel.

The panel is used by the pine64 Pinebook Pro.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Tobias Schramm <t.schramm@manjaro.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200109140742.GA12940@ravnborg.org