Killed all keyboard entry whilst fiddling with xkb
Solution 1:
Boot from the installation media. Once in a live session, open a terminal and mount your root file system on /mnt, then copy over the file from the live session to the mounted root filesystem:
cd /mnt/usr/share/X11/xkb/symbols
sudo cp -a /usr/share/X11/xkb/symbols/pc .
Unmount /mnt and reboot. Everything should work. For added peace of mind, you may want to reinstall xkb-data.