drm/panel: Add DT bindings for Samsung LMS380KF01

This adds device tree bindings for the Samsung Mobile Displays
LMS380KF01 RGB DPI display panel.

Cc: devicetree@vger.kernel.org
Cc: phone-devel@vger.kernel.org
Cc: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714225002.1065107-1-linus.walleij@linaro.org