The IoT Devkit has a yocto repo up here
http://iotdk.intel.com/repos/1.1/iotdk/
I have had great success installing 'missing' packages (git,bison,flex,alsa-utils, etc) from this repo (everything seems to work ok). All you have to do is add the following /etc/opkg/base-feeds.conf
src all http://iotdk.intel.com/repos/1.1/iotdk/all
then run
opkg update
opkg install git