dt-bindings: samsung: Document bindings for Samsung aries boards

Document the binding for Samsung Galaxy S (i9000) phone
and whole Samsung Aries devices family (based on S5PV210).

Also because this is first not Exynos-based devices, document this information
at beginning of file.

Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>