ARM: mvebu: dts: Add dts file for DLink DNS-327L

DNS-327L is a 2-bay NAS with the following specs:
     - 512MiB RAM
     - 128MiB NAND Flash
     - 1 GbE interface (Marvell PHY)
     - 1 rear USB 3.0 port (via PCIe USB 3.0 controller)
     - 2 internal SATA ports handled by the Armada 370:
       	 uses 2 gpios for power control
     - two front 2-color leds (amber + white) for both discs,
        controlled by the SoC
     - One white LED handled by SoC (USB)
     - 3 buttons. Power handled by weltrend, USB and
       RESET (on the bottom) are wired via GPIOs
     - Unidentified i2c device at address 0x13 (via i2cdetect)
     - UART0 providing serial console
     - Weltrend MCU serving for RTC, temperature, fan control,
       and power button handling interfaced via UART1
       (Handled via userspace dns320l-daemon)

Signed-off-by: Andrew Andrianov <andrew@ncrmnt.org>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>