dt-bindings: arm: move berlin binding documentation to syna.txt

Move berlin binding documentation as part of transition from Marvell
berlin to Synaptics SoC.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Acked-by: Rob Herring <robh@kernel.org>

diff --git a/Documentation/devicetree/bindings/arm/marvell/marvell,berlin.txt b/Documentation/devicetree/bindings/arm/syna.txt
similarity index 100%
rename from Documentation/devicetree/bindings/arm/marvell/marvell,berlin.txt
rename to Documentation/devicetree/bindings/arm/syna.txt