ARM: tegra: Add common device-tree for LVDS display panels of Tegra30 ASUS tablets

All Tegra30 ASUS tablets have a similar design pattern in terms of
hardware integration of LVDS display panels, like exactly the same GPIOs
are used for power and reset, etc. Add a common device-tree for LVDS
display panels of Tegra30 ASUS tablets to avoid replicating the
boilerplate panel description.

[digetx@gmail.com: factored out common part into separate patch and wrote commit message]

Co-developed-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Maxim Schwalm <maxim.schwalm@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>