ARM: mvebu: Enable rear eSATA ports of NETGEAR ReadyNAS 2120

NETGEAR ReadyNAS 2120 supports its four main SATA disks via 2
Marvell 88SE9170 SATA controllers connected on the PCIe bus
of the the SoC. The two eSATA ports available at the rear of
the device are handled by the native SATA controller of the
Armada XP SoC powering the NAS. This patch enables the SoC
SATA controller in the .dts file to make those two rear ports
available.
Signed-off-by: NArnaud Ebalard <arno@natisbad.org>
Acked-by: NAndrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/f3876c7a9ef11eb758b9df18c671ee740b8be614.1414250947.git.arno@natisbad.orgSigned-off-by: NJason Cooper <jason@lakedaemon.net>

arch/arm/boot/dts/armada-xp-netgear-rn2120.dts

@@ -137,6 +137,12 @@
 				};
 			};
 
+			/* Two rear eSATA ports */
+			sata@a0000 {
+				nr-ports = <2>;
+				status = "okay";
+			};
+
 			serial@12000 {
 				status = "okay";
 			};