Build for MediaTek Linkit Smart 7688 DevKits

I'm working on a build that includes the manufacturer modifications

and

for the Duo variant

Currently the feeds don't apply at all, and the MRAA library in LEDE is both old and wont compile

there is no trunk support. MTK only provides support for CC

So I'd have to port their modifications. Shrug It's mostly a few scripts and mt7688_pinmux program. Even I can probably manage getting the needed mods to work on LEDE by looking at what was done for the Arduino Yun (most of the modifications are to make the 7688 Duo act like a Yun)