mvebu: dts: a80x0: Sync the DB DTS with standard config A

mvebu: dts: a80x0: Sync the DB DTS with standard config A

Sync the default configuration of Armada-8040-DB with
Marvell u-boot-2015  standard configuration "A" for the same board.
The standard configuration "A" enables 2 PCIe slots on CP0
and 3 PCIe slots on CP1.
This is the main configuration used for u-boot  and Linux tests.
This patch also re-arranges the DTS file entries by grouping
all nodes related to CP0 and CP1.

Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
Cc: Stefan Roese <sr@denx.de>
Cc: Igal Liberman <igall@marvell.com>
Cc: Nadav Haklai <nadavh@marvell.com>
Reviewed-by: Stefan Roese <sr@denx.de>