docs: media: update maintainer-entry-profile for multi-committers

docs: media: update maintainer-entry-profile for multi-committers

As the media subsystem will experiment with a multi-committers model,
update the Maintainer's entry profile to the new rules.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Sean Young <sean@mess.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>