ARM: dts: imx6ul: Add Engicam Is.IoT MX6UL initial support

Is.IoT MX6UL modules are system on module solutions manufactured by
Engicam for IOT connectivity applications with following characteristics:
CPU     NXP i.MX6UL (G2) Cortex-A7@528 MHz
RAM     Up to 512 MB LvDDR3@800MT/s
NAND    256MB (option)
eMMC    4GB (option)
LCD     18 bit parallel
BT      2.1+EDR,Bluetooth 3.0, Bluetooth 4.1 (Bluetooth low energy)
WLAN    IEEE 802.11 b/g/n (single stream n)

Cc: Matteo Lisi <matteo.lisi@engicam.com>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>