staging: panel: Set default parport module param value

Set default parport module param value to DEFAULT_PARPORT so that
a if-block can be avoided.

Signed-off-by: Mariusz Gorski <marius.gorski@gmail.com>
Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>