ARM: dts: Enable USB hub on Arndale

The Arndale has a SMSC USB3503 connected in hardware only mode like a PHY,
support it using the usb-nop-xceiv binding.

Note that due to a regrettable decision to use a regulator to represent
the reset signal this uses a fixed voltage regulator to do that, there
is a plan to use the reset controller binding once that is merged so it
does not seem worthwhile to fix the usb-nop-xceiv driver at this point.

Signed-off-by: Mark Brown <broonie@linaro.org>
Tested-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>