media: Remove incorrect comment from struct v4l2_fwnode_endpoint

struct v4l2_fwnode_endpoint was zeroed previously apart from the endpoint
information itself when the endpoint properties were parsed. Now this
hasn't been the case for a few years so remove the comment.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>