qemu-io: build on all platforms

Since c32d766a, qemu-io should be
portable. It is currently built only on linux and mingw32.

This patch enables qemu-io on all platforms. Tested on FreeBSD.
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

configure

@@ -2087,15 +2087,13 @@ esac
 
 tools=
 if test `expr "$target_list" : ".*softmmu.*"` != 0 ; then
-  tools="qemu-img\$(EXESUF) $tools"
+  tools="qemu-img\$(EXESUF) qemu-io\$(EXESUF) $tools"
   if [ "$linux" = "yes" ] ; then
-      tools="qemu-nbd\$(EXESUF) qemu-io\$(EXESUF) $tools"
+      tools="qemu-nbd\$(EXESUF) $tools"
     if [ "$check_utests" = "yes" ]; then
       tools="check-qint check-qstring check-qdict check-qlist $tools"
       tools="check-qfloat check-qjson $tools"
     fi
-  elif test "$mingw32" = "yes" ; then
-      tools="qemu-io\$(EXESUF) $tools"
   fi
 fi
 echo "TOOLS=$tools" >> $config_host_mak