V4L/DVB (5698): Input: drivers/media - switch to using input_dev->dev.parent

In preparation for struct class_device -> struct device input
core conversion switch to using input_dev->dev.parent when
specifying device position in sysfs tree.

Signed-off-by: Dmitry Torokhov <dtor at mail.ru>
Acked-by: Thierry Merle <thierry.merle@free.fr>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>