[media] firedtv: fix remote control with newer Xorg evdev

After a recent update of xf86-input-evdev and xorg-server, I noticed
that X11 applications did not receive keypresses from the FireDTV
infrared remote control anymore.  Instead, the Xorg log featured lots of

    "FireDTV remote control: dropping event due to full queue!"

exclamations.  The Linux console did not have an issue with the
FireDTV's RC though.

The fix is to insert EV_SYN events after the key-down/-up events.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>