dt-bindings: create arm/nxp folder and move LPC32xx SoC description to it

Create a separate folder for device tree bindings of NXP SoCs devices,
and move lpc32xx.txt to it.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>

diff --git a/Documentation/devicetree/bindings/arm/lpc32xx.txt b/Documentation/devicetree/bindings/arm/nxp/lpc32xx.txt
similarity index 100%
rename from Documentation/devicetree/bindings/arm/lpc32xx.txt
rename to Documentation/devicetree/bindings/arm/nxp/lpc32xx.txt