ramips: Add support for ZTE Q7

ZTE Q7 is a wireless router with SD Card,USB,1 ethernet port and a battery.It used MT7620a SoC.
I can,t find any information about this router on ZTE's website.
But I found this : http://en.cctairmobi.com/plus/list.php?tid=40


This router is the same as ZTE Q7 and later I found that both routers are made by the same company:-D

This patch adds support for it.
Because there is only one port,I disabled VLAN and use eth0 as lan port.
I could only create a sysupgrade firmware because I don't know how the orignal webpage check the uploaded image:-(

Signed-off-by: 郭传鈜 <gch981213@gmail.com>

SVN-Revision: 45208