base-modem: fix warnings with -Wswitch-enum

mm-base-modem.c: In function ‘mm_base_modem_organize_ports’:
  mm-base-modem.c:1088:9: error: enumeration value ‘MM_PORT_TYPE_UNKNOWN’ not handled in switch [-Werror=switch-enum]
   1088 |         switch (mm_port_get_port_type (candidate)) {
        |         ^~~~~~
  mm-base-modem.c:1088:9: error: enumeration value ‘MM_PORT_TYPE_IGNORED’ not handled in switch [-Werror=switch-enum]

src/mm-base-modem.c

@@ -1181,6 +1181,14 @@ mm_base_modem_organize_ports (MMBaseModem *self,
             break;
 #endif
 
+        case MM_PORT_TYPE_UNKNOWN:
+        case MM_PORT_TYPE_IGNORED:
+#if !defined WITH_MBIM
+        case MM_PORT_TYPE_MBIM:
+#endif
+#if !defined WITH_QMI
+        case MM_PORT_TYPE_QMI:
+#endif
         default:
             /* Ignore port */
             break;