V4L/DVB: lirc: use unlocked_ioctl

New code should not rely on the big kernel lock,
so use the unlocked_ioctl file operation in lirc.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>