mm/damon/reclaim: support online inputs update

DAMON_RECLAIM reads the user input parameters only when it starts.  To
allow more efficient online tuning, this commit implements a new input
parameter called 'commit_inputs'.  Writing true to the parameter makes
DAMON_RECLAIM reads the input parameters again.

Link: https://lkml.kernel.org/r/20220429160606.127307-14-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>