arm64: dts: freescale: ten64: add usb hub definition

A device tree binding for the Microchip USB5744 hub controller
was added in commit 02be19e9 ("dt-bindings: usb: Add support
for Microchip usb5744 hub controller").

U-Boot will consume this binding in order to perform the
necessary actions to enable the USB hub ports over I2C.
(We previously used our own out-of-tree driver for
this task)

The Ten64 board does not have any switchable supplies
for the voltage rails utilized by the USB5744, so a
pair of dummy supplies have been added to facilitate
operation with U-Boot's hub driver.

Signed-off-by: Mathew McBride <matt@traverse.com.au>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>