ARM: dts: Add hix5hd2-dkb dts file.

Add dts file for Hisilicon x5hd2 development kit board.

Signed-off-by: Haifeng Yan <yanhaifeng@gmail.com>
Signed-off-by: Jiancheng Xue <jchxue@gmail.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Acked-by: Wei Xu <xuwei5@hisilicon.com>
[olof: Rename dts/dtsi to include hisi prefix]
Signed-off-by: Olof Johansson <olof@lixom.net>