[media] media/rc: Send sync space information on the lirc device

Userspace expects to see a long space before the first pulse is sent on
the lirc device.  Currently, if a long time has passed and a new packet
is started, the lirc codec just returns and doesn't send anything.  This
makes lircd ignore many perfectly valid signals unless they are sent in
quick sucession.  When a reset event is delivered, we cannot know
anything about the duration of the space.  But it should be safe to
assume it has been a long time and we just set the duration to maximum.

Signed-off-by: Austin Lund <austin.lund@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>