ARM: dts: s5pv210: Add node for exynos-rotator

Add node for Exynos Rorator device, so it can be used on all S5Pv210
based devices.

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