arm: kirkwood: add ZyXEL NSA310S device

This patch add ZyXEL NSA310S 1-Bay Media Server

The ZyXEL NSA310S device is a Kirkwood based NAS:

- SoC: Marvell 88F6702 1000Mhz
- SDRAM memory: 256MB DDR2 400Mhz
- Gigabit ethernet: PHY Marvell 88E1318
- Flash memory: 128MB
- 1 Power button
- 1 Power LED (blue)
- 4 Status LED (green)
- 1 Copy/Sync button
- 1 Reset button
- 1 SATA II port
- 2 USB 2.0 ports (front and back)
- Smart fan

Signed-off-by: Gerald Kerma <dreagle@doukki.net>
Signed-off-by: Tony Dinh <mibodhi@gmail.com>
Signed-off-by: Luka Perkov <luka.perkov@sartura.hr>
diff --git a/board/zyxel/nsa310s/Kconfig b/board/zyxel/nsa310s/Kconfig
new file mode 100644
index 0000000..77e734d
--- /dev/null
+++ b/board/zyxel/nsa310s/Kconfig
@@ -0,0 +1,20 @@
+#
+# Copyright (C) 2015
+# Gerald Kerma <dreagle@doukki.net>
+# Tony Dinh <mibodhi@gmail.com>
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+if TARGET_NSA310S
+
+config SYS_BOARD
+	default "nsa310s"
+
+config SYS_VENDOR
+	default "zyxel"
+
+config SYS_CONFIG_NAME
+	default "nsa310s"
+
+endif