Please enable the Mediatek mt7601u wifi driver in the 4.2 tree.
CONFIG_WL_MEDIATEK=y
CONFIG_MT7601U=m
I don't actually use it myself, but remember someone opened an issue in the past about getting a driver included for this wifi dongle, to which the response was something along the lines of, "when it's upstreamed we'll enable it". It got added with 4.2rc3 IIRC.