ARM: dts: armada388-clearfog: split clearfog DTS file

There are two versions of the clearfog - a base and a pro model.  The
base model has an additional PHY on eth1, replacing the DSA switch on
the pro model.  MPP assignments are slightly different.  The base model
also omits the second PCIe, and footprint for a PIC microcontroller.

In order to cater for these differences, move all the existing clearfog
support to a dtsi file before starting to modify it, to make the
following changes more clear.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>