ARM: dts: imx6ull: Add chargebyte Tarragon support

This adds the support for chargebyte Tarragon, which is an Electrical
Vehicle Supply Equipment (EVSE) for AC charging stations
(according to IEC 61851, ISO 15118).

The Tarragon board is based on an i.MX6ULL SoC and is available in
4 variants (Master, Slave, SlaveXT, Micro), which provide more or
less peripherals.

Supported features:
  * 512 MB DDR RAM
  * eMMC
  * Debug UART
  * 100 Mbit Ethernet
  * USB 2.0 Host interface
  * Powerline communication (QCA700x)
  * 2x RS485
  * Digital in- and outputs (12 V)
  * One-Wire master for external temp sensors
  * 2x relay outputs
  * 2x motor interfaces

Link: https://chargebyte.com/products/charging-station-communication/charge-control-c


Signed-off-by: Stefan Wahren <stefan.wahren@chargebyte.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>