arm64: tegra: Add NVIDIA P2597 I/O board support

The NVIDIA P2597 I/O board is a carrier board for the Jetson TX1 module
and together they are also known as the Jetson TX1 Developer Kit. The
I/O board provides an RJ45 connector routed to the network adapter that
is part of the Jetson TX1 module. It exposes many other connectors such
as SATA, USB 3.0, HDMI, JTAG and PCIe, among others, as well. Dedicated
connectors allow display and camera modules to be attached. A full-size
SD slot is provided to extend storage beyond the 32 GiB of eMMC found
on the Jetson TX1 module.

Signed-off-by: Thierry Reding <treding@nvidia.com>