ARM: mvebu: add Device Tree description of xHCI controllers on Armada 38x

The Marvell Armada 38x SoCs contains two xHCI controllers. This commit
adds the Device Tree description of those interfaces at the SoC level,
and also enables the two USB3 ports on the Armada 385 DB platform and
one USB3 port on the Armada 385 RD platform.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1400149062-32661-15-git-send-email-gregory.clement@free-electrons.com


Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>