add support for mt7601 wireless driver

[Liu Jianfeng <liujianfeng1994@gmail.com>]

Since linux-4.2 has contained mt7601: https://github.com/torvalds/linux/tree/master/drivers/net/wireless/mediatek/mt7601u, we can enable it by editing debian/config/config

And due to this bug: https://bugzilla.redhat.com/show_bug.cgi?id=1264631, we should also add the firmware mt7601.bin to a firmware package