arm64: marvell: dts: add PPv2.2 description to Armada 7K/8K

This commit adds the description of the PPv2.2 hardware block for the
Marvell Armada 7K and Armada 8K processors, and their corresponding Armada
7040 and 8040 Development boards.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>