USB: io_ti: fix get_icount for two port adapters

Add missing get_icount field to two-port driver.

The two-port driver was not updated when switching to the new icount
interface in commit 0bca1b9 ("tty: Convert the USB drivers to the
new icount interface").

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/io_ti.c

@@ -2649,6 +2649,7 @@ static struct usb_serial_driver edgeport_2port_device = {
 	.set_termios		= edge_set_termios,
 	.tiocmget		= edge_tiocmget,
 	.tiocmset		= edge_tiocmset,
+	.get_icount		= edge_get_icount,
 	.write			= edge_write,
 	.write_room		= edge_write_room,
 	.chars_in_buffer	= edge_chars_in_buffer,