ARM: dts: keystone: Add minimum support for K2G ICE evm

Add barebones dts support for TI's K2G Industrial Communication Engine evm.
This dts allows the board to boot using a ram based filesystem.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>