Add grml to x64 menu

roles/netbootxyz/templates/menu/live.ipxe.j2

@@ -17,6 +17,7 @@ item live-fatdog ${space} Fatdog64
 item live-fedora ${space} Fedora
 item live-feren ${space} Feren OS
 item live-garuda ${space} Garuda Linux
+item live-grml ${space} Grml
 item live-hrmpf ${space} hrmpf
 item live-k3os ${space} K3OS
 item live-kali ${space} Kali