[legal] Update FSF mailing address in GPL licence texts

Suggested-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/util/disrom.pl

@@ -14,7 +14,8 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, write to the Free Software
-# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301, USA.
 
 use strict;
 use warnings;