arm64: dts: marvell: use reworked NAND controller driver on Armada 7K

Use the new bindings of the reworked Marvell NAND controller driver.
Also adapt the nand controller node organization to distinguish which
property is relevant for the controller, and which one is NAND chip
specific. Expose the partitions as a subnode of the NAND chip.

Remove the 'marvell,nand-enable-arbiter' property, not needed anymore as
the driver activates the arbiter by default for all boards (either
needed or harmless).

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>