media: rc: default to idle on at startup or after reset

Any spaces events received after a reset or startup should be discarded,
so ensure the rc device is in idle mode.

This also makes it much easier to detect incorrect raw events, as we will
do in a following commit.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>