I had the same problem with an Intel Centrino 2230 (Galileo Gen 2) and a Realtek RTL8188CUS USB Wireless Adaptor (Galileo Gen 1)
Removing connman fixed it.
But before you do, maybe you should use AlexT's version of Yocto that includes connection to his repository or manually set up a connection so you can put it back if needed.
opkg remove connman
it will hang a long time on stopping connman, but when you reboot it should be gone
You can check with opkg list |grep connman
I assume from your answer that this solved the problem. Since, according to AlexT and my readings, connman is just the front end for the network applications, removing it shouldn't have any effect on your communications. I probably should also have mentioned that you can always make a copy of your SD card to your computer prior to making any major changes, so if things don't work you can just restore the previous version.
Good luck with your project