ARM: dts: orion5x: add device tree for buffalo linkstation ls-gl

ARM: dts: orion5x: add device tree for buffalo linkstation ls-gl

Add dts file to support Buffalo Linkstation LS-GL
(a.k.a Buffalo Linkstation Pro/Live), which is marvell orion5x based
3.5" HDD NAS.

Product info:
  - (JPN) http://buffalo.jp/products/catalog/item/l/ls-gl/
  - (ENG) http://www.buffalotech.com/products/network-storage/linkstation/linkstation-pro

This device tree is based on the board file:
  arch/arm/mach-orion5x/kurobox_pro-setup.c
However, that board file also support Kurobox Pro, which is not supported by
device tree yet. So the board file is not removed.

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>