serial-port-qcdm: set SEND_DELAY to 0 (bgo #698869)

For some reason a number of ZTE CDMA devices want the whole QCDM
frame in one USB transaction, or at least don't like it being
broken up and sent byte-by-byte with a send delay.  They simply
don't respond.  Since testing indicates that every other QCDM
capable device I've got also handles a zero send delay on both
3.8.8 and 2.6.32, lets just set it to zero for everything,
which should speed things up a bit too.

https://bugzilla.gnome.org/show_bug.cgi?id=698869

src/mm-qcdm-serial-port.c

@@ -231,6 +231,7 @@ mm_qcdm_serial_port_new (const char *name)
                                               MM_PORT_DEVICE, name,
                                               MM_PORT_SUBSYS, MM_PORT_SUBSYS_TTY,
                                               MM_PORT_TYPE, MM_PORT_TYPE_QCDM,
+                                              MM_SERIAL_PORT_SEND_DELAY, (guint64) 0,
                                               NULL));
 }
 
@@ -246,6 +247,7 @@ mm_qcdm_serial_port_new_fd (int fd)
                                               MM_PORT_SUBSYS, MM_PORT_SUBSYS_TTY,
                                               MM_PORT_TYPE, MM_PORT_TYPE_QCDM,
                                               MM_SERIAL_PORT_FD, fd,
+                                              MM_SERIAL_PORT_SEND_DELAY, (guint64) 0,
                                               NULL));
     g_free (name);
     return port;