arm64: dts: fsl: pico-pi: Add a device tree for the PICO-PI-IMX8M

arm64: dts: fsl: pico-pi: Add a device tree for the PICO-PI-IMX8M

TechNexion PICO-PI-IMX8M-DEV evaluation and development kit based on
NXP i.MX8M Quad applications processor. Datasheet can be found at:

https://s3.us-east-2.amazonaws.com/technexion/datasheets/picopiimx8m.pdf

The current level of support yields a working console and is able to boot
userspace from NFS or init ramdisk.

Additional subsystems that are active :
	- Ethernet
	- USB

Cc: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Richard Hu <richard.hu@technexion.com>
Signed-off-by: Andra Danciu <andradanciu1997@gmail.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>