dt-bindings: panel: Add Samsung S6E63M0 panel documentation

This commit adds documentation for Samsung S6E63M0 AMOLED LCD panel
driver.

Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190222175153.20567-1-pawel.mikolaj.chmiel@gmail.com