[media] ati_remote: Delete superfluous input_sync()

It's not necessary, and since both events happen "at the same time"
in response to a single input event, the input device framework prefers
not to have it there.

(It's not a big deal one way or the other, but deleting cruft
is generally a good thing.)

Signed-off-by: George Spelvin <linux@horizon.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>