dt-bindings: Add support for LG LP079QX1-SP0V panel

The LG LP079QX1-SP0V is an 7.9" QXGA TFT with LED Backlight unit and
32 pins eDP interface. This module supports 1536x2048 mode.

Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>