ARM: dts: Use armada-370-xp as a base for armada-xp-98dx3236

The Marvell datasheets refer to the integrated CPU as "Armada-XP". In
reality there are a number of differences to the actual Armada-XP so
rather than including armada-xp.dtsi and disabling many of the IP
blocks. Include armada-370-xp.dtsi and add the required nodes.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>