ARM: dts: imx: add imx7ulp evk support

The NXP i.MX 7ULP Evaluation Kit (EVK) provides a platform for rapid
evaluation of the i.MX 7ULP, which features NXP's advanced implementation
of the Arm Cortex-A7 core, the Arm Cortex-M4 core, as well as a 3D and
2D Graphics Processing Units (GPUs).

The EVK enables HDMI output for simple out-of-the-box to bring up but
allows reconfiguration for MIPI displays. The EVK is designed as a
System-On-Module(SOM) board that connects to an associated baseboard.
The SOM provides 1 GB LPDDR3, 8 MB Quad SPI flash, Micro SD 3.0 card
socket, WiFi/ Bluetooth capability, USB 2.0 OTG with Type C connector
and an NXP PF1550 power management IC (PMIC). The baseboard provides
additional capabilities including a full SD/MMC 3.0 card socket, audio
codec, multiple sensors, an HDMI connector, and an alternate MIPI display
connector. Additionally, the EVK facilitates software development with the
ultimate goal of faster time to market through the support of both
Linux OS and AndroidTM rich operating systems, as well as FreeRTOS.

This patch aims to support the preliminary booting up features
as follows:
GPIO
LPUART
FEC
SD/MMC

See more board details:
https://www.nxp.com/products/processors-and-microcontrollers/


arm-based-processors-and-mcus/i.mx-applications-processors/
i.mx-7-processors/evaluation-kit-for-the-i.mx-7ulp-applications
-processor:MCIMX7ULP-EVK

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: devicetree@vger.kernel.org
Cc: Sascha Hauer <kernel@pengutronix.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>