I have spend a lot of time on this, finally it is working perfect with latest LEDE!!
This firmware also enable sniffer/monitor mode for possible fun.

This driver is more stable than last time one for Linux 4.5, I have used iperf3 test one hour, average speed is greater than 40Mbps — one on board blue antenna, and over 50Mbps for one external antenna. Of course double external antennas will be much faster.

firmware with blob here: http://vonger.cn/misc/vocore2/lede-ramips-mt76x8-vocore2-squashfs-sysupgrade.bin
md5: 9a7ef2de60713cfb7c951ba4a6a92b81

mt7628.ko: http://vonger.cn/misc/vocore2/mt7628.ko for Linux 4.9
iwpriv and iwconfig: http://vonger.cn/misc/vocore2/wireless-tools_29-5_mipsel_24kc.ipk

mt7628.dat: used to config wifi kernel. uncompress and put it to /etc, link here http://vonger.cn/misc/vocore2/wireless.zip

mt7628.dat should in this path /etc/wireless/mt7628/mt7628.dat

PS: unfortunately, because of MTK NDA, I can not public its source code.

How to use?
First of all: insmod mt7628

1. Enable wifi AP mode:

ifconfig ra0 192.168.1.1 up
brctl addif br-lan ra0

2. Enable monitor/sniffer mode(I never use sniffer mode before, maybe it works)

ifconfig mon0 up

3. Enable STA mode…(this need compile iwpriv into the firmware, I did not try)

iwpriv ra0 set SiteSurvey=1
sleep 1
iwpriv ra0 set SiteSurvey=0
iwpriv ra0 get_site_survey

iwpriv ra0 set Channel=11 (must same as your AP, this value can get from "iwpriv ra0 get_site_survey")
iwpriv apcli0 set ApCliEnable=0
iwpriv apcli0 set ApCliAuthMode=WPA2PSK (normally WPA2 personal we use this setting)
iwpriv apcli0 set ApCliEncrypType=AES
iwpriv apcli0 set ApCliSsid=[YOUR SSID]
iwpriv apcli0 set ApCliWPAPSK=[YOUR SSID PASSWORD]
iwpriv apcli0 set ApCliEnable=1

TODO:
make uci work with this driver. Currently have to manually insert the driver and start up it. :p