Which image are you using with your Galileo?
If I'm not mistaken, I believe this library is designed for the eglibc image and it is probably incompatible with the uclibc image. In case you are using the uclibc image I suggest you to reach out to EmutexLabs for help in installing this library.
I'm using the image mentioned here (SD-Card Linux Image.zip):
I guess it should work, since i'm using Yocto.
Installing on Yocto Linux
If you are using the standard Yocto Linux distribution for Edison or the one for Galileo provided by (Intel Makers) then no additional OS preparation is required.
wiring.pycan be installed by following step 2 in the previous section.
To install the module manually first grab the code from GitHub:
Then install it as follows:
$ tar zxvf master.tar.gz
$ cd wiring-x86-master/
$ sudo python setup.py install
After using either installation method check that the everything went okay
by running the following command. It should have no errors:
$ python -c 'import wiringx86'
I think the issue is that you are probably using the uclibc image, I suggest you to use the eglibc image that can be downloaded from Intel® Galileo Downloads. But just like in Wiring-x86 error, I would strongly suggest you to use mraa instead of Wiring-x86 since it is constantly updated and has a lot more features while Wiring-x86 hasn't been updated in around a year.