K2G SoC family is the newest version of the Keystone family of processors.

The technical reference manual for K2G can be found here:
http://www.ti.com/lit/ug/spruhy8/spruhy8.pdf

Add new bindings for K2G and the K2G evm. Also document these new bindings.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NFranklin S Cooper Jr <fcooper@ti.com>
Signed-off-by: NSantosh Shilimkar <ssantosh@kernel.org>