Add dummy ops for serial debug port.
Add setting of c_ispeed/c_ospeed as suggested by Alan Cox.
Signed-off-by: Hinko Kocevar <hinko.kocevar@cetrtapot.si>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>