el8: add xorrisofs as option

Author: weizhouapache

packaging/el8/cloud.spec

@@ -76,7 +76,7 @@ Requires: sudo
 Requires: /sbin/service
 Requires: /sbin/chkconfig
 Requires: /usr/bin/ssh-keygen
-Requires: (genisoimage or mkisofs)
+Requires: (genisoimage or mkisofs or xorrisofs)
 Requires: ipmitool
 Requires: %{name}-common = %{_ver}
 Requires: (iptables-services or iptables)