The GeoIP section of win32utils/build.txt is outdated and needs to be revised to reflect the current state of things:

Step 5: Download and build GeoIP

  Geographic ("geoip") ACLs require libGeoIP. If you wish to build BIND 9
  without support for this feature, skip to step 6.

  The libGeoIP source code is available from:

    https://github.com/maxmind/geoip-api-c/releases.

  As of this writing, the current version of libGeoIP is 1.6.0.  There
  is a known bug in this and all prior versions which prevents it from
  building a suitable DLL with thread support on Windows.  You can apply
  the patch file bind9/win32utils/GeoIP.diff to address the problem.
  This patch has been submitted upstream, and will be included in
  future versions of libGeoIP.