Documentation: coresight: Update the generic device names

Update the documentation to reflect the new naming scheme with
latest changes.

Reported-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>