ARM: Kirkwood: add DT support for d2 Network v2

ARM: Kirkwood: add DT support for d2 Network v2

This patch adds DT support for the LaCie NAS d2 Network v2 (d2net_v2).
Most of the hardware characteristics are shared with the 2Big and 5Big
Network v2 boards.

- CPU: Marvell 88F6281 1200Mhz
- SDRAM memory: 256MB DDR2 400Mhz
- 2 SATA ports: internal and eSATA
- Gigabit ethernet: PHY Marvell 88E1116R
- Flash memory: SPI NOR 512KB (Macronix MX25L4005A)
- i2c EEPROM: 512 bytes (24C04 type)
- 2 USB2 ports: host and host/device
- 1 push button
- 1 power switch
- 1 SATA LED (bi-color, blue and red)

Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1404830545-15581-3-git-send-email-simon.guinot@sequanux.org
Signed-off-by: Jason Cooper <jason@lakedaemon.net>