A better way to do it, is to use the package.
cd into the dir where you downloaded lede-project
$ mkdir package/libs/libugpio/
$ cd package/libs/libugpio/
$ wget https://dev.openwrt.org/export/35269/packages/libs/libugpio/Makefile
$ cd -
$ make menuconfig
save changes and exit
then build it
$ make -j4
After that, your dependencies shall be resolved.
Remember that you also need to install libugpio on the omega. You can do so by opkg install libugpio