Docs/admin-guide/mm/damon/usage: remove unnecessary sentences about supported address spaces

Brief explanation of DAMON user space tool and sysfs interface are
unnecessarily and repeatedly mentioning the list of address spaces that
DAMON is supporting.  Remove those.

Link: https://lkml.kernel.org/r/20230616191742.87531-5-sj@kernel.org


Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>