selftests/damon/_damon_sysfs: support schemes_update_tried_regions

Implement schemes_update_tried_regions DAMON sysfs command on
_damon_sysfs.py, to use on implementations of future tests for the
feature.

Link: https://lkml.kernel.org/r/20240625180538.73134-3-sj@kernel.org


Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>