gtk-doc.make: Remove the file
gtk-doc.make: Remove the file

Now that we're using gtkdocisze as part of autogen.sh, there's no reason
to keep our own gtk-doc.make file.

Signed-off-by: Fabiano Fidêncio <2931bae082ef9bc04523ba759c03a4778316d48f@redhat.com>
Reviewed-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

libvirt/libvirt-glib,libvirt/libvirt-glib,libvirt/libvirt-glib