[media] tvp5150: Make debug module parameter visible in sysfs

Set permissions on the debug module parameter to make it appear in sysfs.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>