dt-bindings: arm: samsung: document bindings for P4 Note family board

Document the GT-N8010/GT-N8013 device binding and the P4 Note common
binding that it is based on.

Signed-off-by: Martin Jücker <martin.juecker@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20201113212525.13455-2-martin.juecker@gmail.com


Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>