TTY: synclink_cs, use dynamic tty devices

This allows us to provide the tty layer with information about
tty_port for each link. And it also allows us to get rid of the
remove_device loop in synclink_cs_exit because we had to reorder
pcmcia and tty driver registration in init. This was because we need
to have serial_driver initialized when calling
tty_port_register_device from pcmcia ->probe.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>