at-serial-port: no need to pass port type when creating the object

We'll just specify the port is AT, not primary or secondary

src/mm-base-modem.c

@@ -238,7 +238,7 @@ mm_base_modem_grab_port (MMBaseModem *self,
             int i;
 
             /* AT port */
-            port = MM_PORT (mm_at_serial_port_new (name, ptype));
+            port = MM_PORT (mm_at_serial_port_new (name));
 
             /* Set common response parser */
             mm_at_serial_port_set_response_parser (MM_AT_SERIAL_PORT (port),

src/mm-port-probe.c

@@ -588,8 +588,7 @@ serial_open_at (MMPortProbe *self)
 
     /* Create AT serial port if not done before */
     if (!task->serial) {
-        task->serial = MM_SERIAL_PORT (mm_at_serial_port_new (self->priv->name,
-                                                              MM_PORT_TYPE_PRIMARY));
+        task->serial = MM_SERIAL_PORT (mm_at_serial_port_new (self->priv->name));
         if (!task->serial) {
             port_probe_run_task_complete (
                 task,

src/mm-port.h

@@ -31,6 +31,7 @@ typedef enum { /*< underscore_name=mm_port_type >*/
     MM_PORT_TYPE_UNKNOWN = 0x0,
     MM_PORT_TYPE_AT,
     MM_PORT_TYPE_IGNORED,
+    MM_PORT_TYPE_AT,
     MM_PORT_TYPE_QCDM,
 
     MM_PORT_TYPE_LAST = MM_PORT_TYPE_QCDM