V4L/DVB (5407a): Update feature-removal-schedule.txt: remove VIDIOC_S/G_MPEGCOMP

Those two experimental APIs never worked fine nor, afaik, were 
implemented at the apps. Their functionalities were implemented by other 
means.
So, let's remove those obsolete stuff.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>