ARM: dts: Convert Linkstation Mini to Device Tree

The title says it all. The name of the dts file as been changed to
better reflect the manufacturer's device name (LS-WSGL), rather than
the original "lsmini", which exists in a kirkwood version too.

[gregory.clement@free-electrons.com]: use tab instead of space to
indent dts at line 185. Reslove merge conflict with patch "ARM: dts:
orion5x: add buffalo linkstation ls-wtgl" in the file
arch/arm/boot/dts/Makefile.

Signed-off-by: Benjamin Cama <benoar@dolka.fr>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Alexey Kopytko <alexey@kopytko.ru>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>