media: lirc: lirc mode ioctls deal with current mode

The ioctl change the current mode or return the current mode; they
do not tell you which modes are possible (use the lirc features
ioctl for that).

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