[media] lirc_dev: return POLLHUP and POLLERR when device is gone

Most drivers return both values when the device is gone.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>