arm64: dts: marvell: add optee FW definitions

Add reserved memory and ARM firmware definitions for optee
memory region in Marvell Armada SoCs to avoid protected memory
access.

Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory Clement <gregory.clement@bootlin.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>