arm: mvebu: Clarify (e)SATA ports info in NETGEAR ReadyNAS 102 .dts file

On NETGEAR ReadyNAS 102, the two disks are connected to the external
Marvell 88SE9170 SATA Controller connected to the PCIe bus. The rear
eSATA port is connected to the native Armada 370 SATA controller.

This patch updates the comments in .dts file wrt SATA interfaces and
reduces the number of ports for native Armada 370 interface from 2
to 1.

Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/4af680f9a68281755e31df2491f0590046138230.1414185031.git.arno@natisbad.org


Signed-off-by: Jason Cooper <jason@lakedaemon.net>