ar71xx: add user-space support for GL.iNet v1

Patch is based on http://patchwork.openwrt.org/patch/5273/

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Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Michel Stempin <michel.stempin@wanadoo.fr>
Signed-off-by: Mark Janssen <mark@sig-io.nl>
Signed-off-by: alzhao <alzhao@gmail.com>
Patchwork: http://patchwork.openwrt.org/patch/5652/


Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 41619