arm64: dts: marvell: initial DT description of Armada 7K/8K CP110 master

This commit adds an initial Device Tree description for the CP110
master that is found in the Armada 7K and 8K SoCs. This initial
description describes:

 - the system controller (to provide clocks)
 - three PCIe interfaces
 - the SATA interface
 - the I2C controllers
 - the SPI controllers

For the record, the organization of the SoCs is as follows:

 - 7020: dual-core AP, one CP110 (master)
 - 7040: quad-core AP, one CP110 (master)
 - 8020: dual-core AP, two CP110s (master and slave)
 - 8040: quad-core AP, two CP110s (master and slave)

For this reason, all of the 7020, 7040, 8020 and 8040 include
armada-cp110-master.dtsi. When support for the second CP110 (slave)
used in 8020 and 8040 will be added, the .dtsi files for those SoCs
will in addition include armada-cp110-slave.dtsi.

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