ARM: dts: kirkwood: add device tree for buffalo linkstation ls-qvl

ARM: dts: kirkwood: add device tree for buffalo linkstation ls-qvl

Add dts file to support Buffalo Linkstation LS-QVL,
which is marvell kirkwood based 4-bay 3.5" HDD NAS.
Product info:
  - (JPN) http://buffalo.jp/product/hdd/network/ls-qvl_r5/
  - (ENG) http://www.buffalotech.com/products/network-storage/home-and-small-office/linkstation-pro-quad

Signed-off-by: Mario Lange <mario_lange@gmx.net>
Signed-off-by: Roger Shimizu <rogershimizu@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>