[media] v4l2-flash-led: remove unused ops

These ops are deprecated and should not be used anymore (and in fact
they are not used at all).

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>